JP2002359239A - Method for manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an insulation film, having a low dielectric constant and a sufficient mechanical strength. SOLUTION: A method for manufacturing a semiconductor device comprises a step of coating a precursor of a substance for constituting an interlayer insulating film 3 or an insulation film stock, containing the substance on a semiconductor substrate 1, steps of irradiating the insulating film stock with an electron beam, while heating the substrate 1 in a reaction vessel, and curing the stock. At this time, at least on of the pressure in the vessel, the temperature of the substrate 1, the species of gas to which the substrate is exposed, the flow rate of the gas to be introduced into the container, the position of the substrate 1 and the amount of electrons which is incident per unit time on the substrate is changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device having an insulating film formed by a coating method.

[0002]

2. Description of the Related Art As wiring dimensions have become smaller due to miniaturization of semiconductor elements, the capacitance between wirings has been increasing.
In recent years, this type of increase in inter-wiring capacitance has been greatly affecting the operation speed of devices.

Conventionally, a silicon oxide film formed by thermal CVD or plasma CVD has been used as an interlayer insulating film of a semiconductor device. However, in recent years, it has been required to apply a low dielectric constant film such as an organic silicon oxide film or an organic film containing no silicon to the interlayer insulating film in order to reduce the capacitance between wirings.

The relative dielectric constant of a general silicon oxide film (P-SiO ₂ ) obtained by conventional plasma CVD is 4.
It is about 1. Further, the relative dielectric constant of a silicon oxide film (FSG film) obtained by adding fluorine (F) to this and lowering the dielectric constant is 3.3. This is thermal CVD or plasma C
This is the lower limit of the relative dielectric constant of the insulating film formed by VD.

On the other hand, by using a low dielectric constant film such as the above-mentioned organic silicon oxide film, the relative dielectric constant becomes 2.4.
An interlayer insulating film of about -2.8 can be realized. However, there are many problems in the practical use of these low dielectric constant films at present. One of the serious problems is that the mechanical strength of the film is low. When the mechanical strength of the film is low, cracks occur in the film during and after film formation, or peeling of the film occurs during the CMP process.
When cracks or peeling occur, it becomes difficult to produce highly reliable wiring.

Most of low dielectric constant films such as an organic silicon oxide film are formed by a method using coating. In the above method, for example, a liquid material called a varnish in which a precursor of a substance constituting a low dielectric constant film is dissolved in a solvent is applied on a substrate, and then the liquid material is heated to evaporate the solvent and crosslink the precursor. It is to do. Here, the precursor refers to a series of substances at a stage before the product of interest.

Next, a sequence of a conventional method of forming an insulating film by a coating method will be specifically described below using a polymethylsiloxane film (organic silicon oxide film) as an example. The outline of the above forming method is as follows (steps ac).

Step a: Application of varnish Step b: Heat treatment at about 80-200 ° C. for about 1 minute. Step c: heat treatment at about 400-450 ° C. for about 30-60 minutes.

The above forming method will be described in more detail. First, a varnish in which polymethylsiloxane is dissolved in a solvent is applied on a substrate to be processed by a spin coat method using a coater to form a coating film (step a). Next, the substrate to be processed is heated at a temperature of 80 to 200 ° C. for about 1 minute (step b). Finally, the substrate to be processed is
Heating at a temperature of -450 ° C for 30 minutes (step c) gives a polymethylsiloxane film.

In the above sequence (steps ac),
Step b is responsible for fixing the film material by solvent volatilization, and step c is responsible for the treatment of forming cross-links between polymethylsiloxane molecules.

The characteristics of the polymethylsiloxane film formed by the above forming method will be described below.

Generally, such an insulating film has a low dielectric constant, but has a low density and / or a high porosity. Therefore, the polymethylsiloxane film has a drawback of low mechanical strength.

Further, when such an insulating film having a low mechanical strength is formed by the above-mentioned method, a problem occurs that a crack is formed at a certain thickness or more. The limit thickness at which cracks do not occur is called crack resistant film thickness.

Here, the characteristics of the interlayer insulating film of the semiconductor device are better as the relative dielectric constant is lower and the crack resistance is larger. The polymethylsiloxane film formed by the above-described conventional forming method has a crack-resistant film thickness of 1200 nm when the relative dielectric constant is 2.8. Therefore, a polymethylsiloxane film formed by a conventional forming method is not sufficient as a characteristic of an interlayer insulating film of a semiconductor device.

Here, the factors causing cracks in the low dielectric constant polymethylsiloxane film formed by the conventional forming method will be described below. The causes of the cracks are that the film having low mechanical strength generates internal stress due to film shrinkage during the crosslinking reaction, and that thermal stress is applied during film formation.

In the case of a polymethylsiloxane film, a crosslinking reaction occurs due to dehydration condensation, so that the film shrinks during the reaction, and this becomes residual stress of the film after film formation. Also,
At the time of the cross-linking reaction by heat treatment, film shrinkage occurs while the material is thermally expanded, and when this film is cooled to room temperature, shrinkage due to temperature decrease is applied. As a result, the residual stress of the film is further increased. In addition, the thermal stress applied to the temperature rise and fall causes bridging defects and an increase in porosity, which further weakens the mechanical strength of the originally brittle film.

More recently, as a method of curing a coating film, as disclosed in Japanese Patent Application Laid-Open No. 10-303190, for example, a resin is applied, a part of a solvent is volatilized, and a high energy ray is applied at about room temperature. There has been proposed a method of irradiating a coating film to cure the coating film and then subjecting the coating film to a high-temperature heat treatment. According to the above method, an insulating film having excellent coverage and flatness can be obtained.

However, in order to form silica (silicon oxide film) having excellent coverage and flatness by the above-described method, a high energy ray of 165 keV is applied to the resin. Although the coating film can be cured by irradiation with such a high-level high-energy beam, the network of the structure of the precursor in the coating film cannot be deformed. That is, in the above method, the dielectric constant of the coating film cannot be reduced, and the coating film cannot have desired mechanical strength. Further, there is no description in the above-mentioned gazette about a reduction in the dielectric constant of the coating film or the like, nor is there any description suggesting this.

Furthermore, the method of forming a coating film using only one of the heat treatment and the electron beam irradiation has a problem that it takes a long time until the crosslinking reaction of the precursor is completed. For example, it takes about 30 minutes to about 1 hour to complete the crosslinking reaction of the precursor.

[0020]

As described above, an insulating film having a low dielectric constant formed by a coating method has been proposed in order to reduce the capacitance between wirings. However, the low dielectric constant insulating film formed by the conventional coating method has a problem that the mechanical strength is insufficient.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a semiconductor device having an insulating film having a low dielectric constant and sufficient mechanical strength and a method of manufacturing the same. To provide.

[0022]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, typical ones are briefly described as follows. That is, in order to achieve the above object, a method for manufacturing a semiconductor device according to the present invention includes a step of preparing a substrate to be processed and a step of forming an insulating film on the substrate to be processed. Is a step of applying a precursor of a substance constituting the insulating film or an insulating film raw material containing the substance on the substrate to be processed, and heating the substrate to be processed in a reaction vessel, Irradiating the insulating film raw material with an electron beam, and curing the insulating film raw material, when the insulating film raw material is irradiated with the electron beam, the pressure in the reaction vessel, the pressure of the substrate to be processed; Temperature, the gas type to which the substrate is exposed, the flow rate of the gas introduced into the reaction vessel, the position of the substrate to be processed, and the amount of electrons incident on the substrate to be processed per unit time. The step of varying at least one Characterized in that it comprises a.

According to the study of the present inventors, while heating the substrate to be processed, changing the parameters such as the pressure in the reaction vessel while irradiating the insulating film material with an electron beam. As a result, it was found that an insulating film having a low dielectric constant and sufficient mechanical strength was obtained. This will be described in more detail in the embodiments of the present invention.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

First, a description will be given of a method of forming a coating film using heat treatment and electron beam irradiation, which is the basis of the present embodiment described below. In the above-described formation method, a liquid material (varnish) obtained by dissolving a film material or a precursor thereof in a solvent is applied on a substrate, and then the liquid material applied on the substrate is subjected to heat treatment and electron beam irradiation treatment. It is to be cured. Two typical examples of the sequence of the method for forming the coating film are shown below.

[Sequence 1] Step 1: coating Step 2: heat treatment + electron beam irradiation treatment [Sequence 2] step 1: coating Step 2: heat treatment + electron beam irradiation treatment Step 3: heat treatment The operation in the case where the line irradiation is used will be described. As a form of applying energy to the film material, electron beam irradiation has the following characteristics as compared with heat treatment.

First, an electron beam can give a much higher energy to the film material than the heat treatment. The energy given by the heat treatment is at most several eV or less, while the electron beam generally used for irradiation treatment is about 5 eV.
It has an energy of -200 keV.

Of course, the electron beam that has entered the film material causes a cascade due to collisions, and loses energy while generating secondary electrons and X-rays. Therefore, not all of the energy originally possessed by the electron beam can directly participate in the reaction. However, the energy that the electron beam can give to the film material is still significantly higher than that of the heat treatment.

When electron beam irradiation is performed, energy that cannot be obtained by heat treatment is applied to the film material, so that a cross-linking reaction of the precursor of the film material proceeds effectively or a molecular chain or the like that cannot be cut by heat energy. The group can be cleaved.

When electron beam irradiation is performed, generally, a cross-linking reaction between molecules and a breaking of molecular chains or separation of groups occur simultaneously. Which occurs at what rate depends on the type of material molecule. Further, by combining electron beam irradiation and heat treatment, even when a molecular chain is broken or a group is separated, the breaking point becomes a new cross-linking point and further cross-linking proceeds.

As described above, by using electron beam irradiation, it is possible to carry out a cross-linking reaction between molecules of a film material, which cannot be realized only by a heat treatment, and a cleavage of a molecular chain or separation of a group.

Based on the effect of the electron beam irradiation described above, the effect when the electron beam irradiation is used for forming an insulating film having a low dielectric constant will be described. In the crosslinking reaction by electron beam irradiation, high energy is given, so that the crosslinking reaction is effectively promoted.

Further, by using electron beam irradiation,
An effective crosslinking reaction can be performed at a low temperature. Therefore, an increase in crosslinking defects and porosity due to thermal stress during temperature rise and fall is suppressed, and a film having high mechanical strength is formed.

From the viewpoint of the molecular structure, the use of the electron beam irradiation treatment enables the crosslinking at a crosslinking point different from the crosslinking by the heat treatment, so that the molecular structure having high mechanical strength which cannot be obtained by the heat treatment. Is generated.

Regarding the curing of a coating film using electron beam irradiation, for example, Japanese Patent Publication No. 11-505670 discloses a method of curing an SOG material on a semiconductor substrate by heating the SOG material to a temperature lower than about 250 ° C. A method of irradiating an SOG material with an electron beam while heating at a low temperature is disclosed.

Japanese Unexamined Patent Application Publication No. 11-506873 discloses a method for curing a dielectric substance such as siloxane on a silicon wafer by using electron beam irradiation to obtain excellent dielectric properties, density, uniformity, etc. It is disclosed that a film having

Further, Japanese Patent Application Laid-Open No. 10-107026 discloses an SOG made of HSQ (Hydrogen silsesquioxane).
While heating the layer at a temperature from room temperature to about 500 ° C., the SO 2
There is disclosed a method of curing an SOG layer in which the G layer is exposed to an electron beam and cured to perform an insulating action between metal wirings and a flattening action.

In this embodiment, as will be described in detail later, in a method of forming an insulating film in which a heat treatment step and an electron beam irradiation processing step are combined, a plurality of predetermined parameters are set at the time of electron beam irradiation in the electron beam irradiation processing step. Change at least one of them.

The plurality of predetermined parameters include a pressure in the reaction vessel, a temperature of the substrate to be processed, a gas type to which the substrate is exposed, a flow rate of the gas introduced into the reaction vessel,
These are the position of the substrate to be processed and the amount of electrons incident on the substrate to be processed per unit time.

That is, the present inventors have achieved excellent crack resistance by changing at least one of a plurality of predetermined parameters, and have also been able to perform various processes such as dry etching, dry ashing, and CMP. And found a method of easily obtaining an insulating film having a low dielectric constant and excellent in resistance.

The method of the present embodiment is characterized in that predetermined parameters are changed during the electron beam irradiation processing as described above, and the above-mentioned Japanese Patent Publication No. 11-505670 and Japanese Patent Publication No.
This method is significantly different from the methods disclosed in Japanese Patent No. 6872, Japanese Patent Application Laid-Open No. 10-107026, and the like.

Further, as described in detail below, at least one of the pre-heat treatment and the post-heat treatment may be performed in the same vessel as the reaction vessel for performing the electron beam irradiation treatment, continuously with the method of forming the coating film. . The pre-heat treatment and the post-heat treatment are heat treatments involving at least one variation of a plurality of predetermined parameters.

The plurality of parameters include the pressure in the reaction vessel, the temperature of the substrate to be processed, the type of gas to which the substrate is exposed, the flow rate of the gas introduced into the reaction vessel, and the Position.

In the method of the present embodiment, the pre-heat treatment and the post-heat treatment which are continuous with the above-mentioned electron beam irradiation treatment are performed in the same vessel as the reaction vessel which carries out the electron beam irradiation treatment as described above. In terms of varying a plurality of predetermined parameters, Japanese Patent Application Laid-Open No. H11-505670,
Japanese Unexamined Patent Publication No. Hei 11-506873, Japanese Unexamined Patent Publication No. Hei 10-107
The method is significantly different from the method disclosed in Japanese Patent No. 026 or the like.

The electron beam irradiation causes the molecular chains of the film material to be cut and the groups to be separated, and the heat treatment used in combination with the electron beam irradiation promotes the crosslinking reaction, and adjusts the relationship with the cutting and separation by the electron beam irradiation. Can be taken. As a result, a network structure having high mechanical strength is generated in the film material, and the crack resistance of the insulating film having a low dielectric constant is improved.

In the electron beam irradiation step, it is important to irradiate the film material with an appropriate dose of electron beam so that the molecular chains are not cut off simultaneously with the crosslinking and the separation of the groups does not proceed too much.

In the case of many coating materials, it is often possible to form a better insulating film by performing a heat treatment before the electron beam irradiation treatment and positively fixing the film material by evaporating the solvent.

Next, an embodiment will be described with reference to the drawings.

(First Embodiment) FIGS. 1 (a) -1 (c)
FIG. 3 is a cross-sectional view illustrating a manufacturing process of the semiconductor device according to the first embodiment of the present invention.

First, as shown in FIG. 1A, a base insulating film 2 is formed on a surface of a semiconductor substrate 1 on which elements are integrated, and then the base insulating film 2 is heated and irradiated with an electron beam. An interlayer insulating film 3 is formed on 2. A specific method for forming the interlayer insulating film 3 will be described later.

Next, as shown in FIG. 1B, a wiring groove having a desired size and shape is formed in a predetermined portion of the interlayer insulating film 3, and is formed in the wiring groove by a well-known CMP process. The barrier metal 4 and the metal wiring 5 are formed, and the interlayer insulating film 3, the barrier metal 4 and the metal wiring 5 are formed.
The surface of is flattened. Here, as the metal wiring 5, C
Cu wiring mainly containing u is used.

Thereafter, as shown in FIG. 1C, a barrier insulating film 6 made of SiN or SiC is formed on the surfaces of the interlayer insulating film 3, the barrier metal 4 and the metal wiring 5 whose surfaces are flattened. .

Next, a method for forming the interlayer insulating film 3 will be specifically described. The outline of the above forming method is as follows (Step 1-4).

Step 1: A varnish is applied on the semiconductor substrate 1 by spin coating. Step 2: The semiconductor substrate 1 is subjected to a heat treatment at 80 ° C. for 1 minute. Step 3: The semiconductor substrate 1 is subjected to a heat treatment at 200 ° C. for 1 minute. Step 4: An electron beam irradiation treatment is performed while heating the semiconductor substrate 1 in a reduced-pressure nitrogen atmosphere to form the interlayer insulating film 3.

The above forming method will be described in more detail. First, on the surface of the base insulating film 2 on the semiconductor substrate 1,
A varnish in which polymethylsiloxane as a film material precursor is dissolved in a solvent is applied by a spin coat method using a coater to form a coating film (Step 1). The solvent is
For example, PGPE (propylene glycol monopropyl ether).

Next, the semiconductor substrate 1 is placed on a hot plate which is set in the same container as the reaction container for performing the electron beam irradiation treatment and is kept at 80.degree. This state is 1
The coating film is subjected to a heat treatment at 80 ° C. for 1 minute by holding the coating film for 1 minute (Step 2).

Next, while the semiconductor substrate 1 is placed on the hot plate, the temperature of the hot plate is set to 20.
Keep at 0 ° C. By holding this state for one minute, in the same container as the reaction container for performing the electron beam irradiation treatment,
A heat treatment at 200 ° C. for 1 minute is performed on the coating film (Step 3).

In the above step 2 or step 3, the solvent contained in the coating film formed in step 1 is removed, and the coating film is fixed on the semiconductor substrate 1.

Thereafter, about 20 slm of nitrogen is introduced into the reaction vessel, and the semiconductor substrate 1 is placed in a reduced pressure nitrogen atmosphere.
While placed on a hot plate maintained at 0 ° C,
The coating film is irradiated with an electron beam to form an interlayer insulating film 3 (Step 4).

At the time of electron beam irradiation in step 4, in this embodiment, the pressure in the reaction vessel is set to 40 Torr and 60 Torr.
r was varied in two stages. That is, for about 90 seconds from the start of electron beam irradiation, the pressure in the reaction vessel is set to 40 Torr, and the amount of incident electrons per unit time (hereinafter, referred to as irradiation amount) is set to about 5 μC / cm ² · sec. After that, for about 30 seconds from the end of the electron beam irradiation to the end, the pressure in the reaction vessel was set to 60 Torr, and the irradiation amount was set to about 4 μC / cm ² · sec. The energy of the electron beam is 1 to 15 keV. Also, the total amount of electrons incident on the semiconductor substrate (hereinafter referred to as the total irradiation amount)
Was set to 500 μC / cm ² . The total irradiation amount is not limited to the above value, and may be any value as long as the polymethylsiloxane film does not deteriorate.

Next, an electron beam irradiation apparatus used in this embodiment and the following embodiments will be described with reference to FIG.

At least one electron beam generator 22 is provided above the reaction vessel 21 for performing the electron beam irradiation treatment. The electron beam generator 22 is separated from the reaction vessel 21 by a partition wall 23, and the electron beam 24 is And is introduced into the reaction vessel 21. The electron beam generator 2 is located below the reaction vessel 21.
A hot plate 25 is installed so as to face the lower part of the second plate 2. FIG. 2A shows that the number of the electron beam generators 22 is one,
FIG. 2B shows an apparatus having a plurality of electron beam generators 22.

A semiconductor substrate 1 on which a coating film is formed is placed on a hot plate 25, and the semiconductor substrate 1 is irradiated with an electron beam 24 under desired conditions. Here, the hot plate 25 is connected to a control device (not shown), and the hot plate 25 is maintained at a desired temperature by the control device. By using the hot plate 25, the semiconductor substrate 1 placed thereon is maintained at a substantially uniform temperature, and the uniformity of processing is achieved.

On the other hand, examples of electron beam irradiation apparatuses that are already commercially available include, for example, ElectronC of Electrovision of the United States.
ure (TM) device. Plasma is used for the electron beam source of the above-mentioned apparatus. Electrons in the plasma are extracted into the reaction vessel through the mesh, and the electron beam generator and the reaction vessel are always in the same atmosphere.

Therefore, when a gas containing an organic component is generated from the film to be processed by the electron beam irradiation treatment, the pressure in the discharge region changes suddenly. When the pressure in the discharge region changes suddenly, the electron beam source becomes unstable. As a result, uniform electron beam irradiation becomes impossible. Therefore, when the above-described apparatus is used, problems such as variations in the properties of the fired film, for example, dielectric constant, mechanical strength, and the like occur.

On the other hand, the electron beam irradiating apparatus used in the present embodiment comprises a partition wall 2 between an electron beam generator 22 as an electron beam source and an object to be irradiated (semiconductor substrate 1 on which a coating film is formed).
3 is provided, and the electron beam 24 irradiates the irradiation object through the partition wall 23. Therefore, the influence of the gas generated from the irradiation object on the electron beam generating unit 22 is suppressed by the partition wall 23. As a result, it is possible to irradiate the irradiation target with the uniform electron beam 24, and it is possible to eliminate variations in the characteristics of the film after firing.

The interlayer insulating film 3 formed by the above method is formed by crosslinking by dehydration condensation of a precursor contained in the raw material. At the time of the crosslinking, film shrinkage occurs. Residual stress occurs.

When the coating film is hardened only by heat treatment as in the prior art, the coating film contracts while the semiconductor substrate is thermally expanded. Therefore, when the coating film is cooled to room temperature, the shrinkage of the semiconductor substrate is applied to the coating film when the temperature is lowered, and the residual stress is further increased. The residual stress as described above is one of the causes of crack generation during or after film formation. Therefore, in order to reduce the residual stress, the process 4
Is desirably performed by setting the substrate temperature to 500 ° C. or lower.

However, if the temperature is too low, a crosslinking reaction such as a dehydration reaction does not proceed, and a desired mechanical strength cannot be obtained.
According to the study of the present inventors, at the time of electron beam irradiation, at least 200 ° C.
It was found that the above heating temperature was necessary. From the above, the heating temperature was set to 400 ° C. in the present embodiment.

Further, when performing Step 4, it is necessary to set the pressure in the reaction vessel to 400 Torr or less and the oxygen concentration to 100 ppm or less so that the surface of the coating film is not oxidized by oxygen in the atmosphere. . In this embodiment, the electron beam irradiation is performed in a nitrogen atmosphere of 40 Torr or 60 Torr.

In order to maintain the uniformity of electron beam irradiation under the above conditions, in the present embodiment, the electron beam generator 2
The hot plate 25 was set at a position 75 mm from the lower end of No. 2 and irradiated with an electron beam.

The characteristics of the insulating film (polymethylsiloxane film) formed by the method of this embodiment will be described.

Table 1 shows the method, the method A (heat treatment only), the method B (heat treatment and electron beam irradiation, the pressure in the reaction vessel of 40 Torr) and the method C (heat treatment and electron beam irradiation, The relative dielectric constant and crack-resistant film thickness of each insulating film (polymethylsiloxane film) formed at a pressure of 60 Torr are shown. In method B, the irradiation dose is about 5 μC / c
m ² · sec, and the electron beam irradiation time was 120 seconds. In method C, the irradiation amount was about 4 μC / cm ² · sec, and the electron beam irradiation time was 120 seconds. The relative permittivity was measured using a mercury probe method. The crack-resistant film thickness is a film thickness when cracks are observed visually or by an optical microscope.

[0075]

[Table 1]

The insulating film formed by the method of the present embodiment has a thickness of about 3.0 which is almost equal to that of the insulating film formed by the method A.
Having a relative dielectric constant of With respect to the crack-resistant film thickness, the insulating film formed by the method of the present embodiment was improved by 1.5 times as compared with the insulating film formed by the method A.

The insulating film formed by the method B is obtained by the method A
Has a relative dielectric constant of about 3.0, which is about the same as that of the insulating film formed by the above method. Regarding the crack-resistant film thickness, it was found that the insulating film formed by the method B improved only 1.1 times as much as the insulating film formed by the method A.

The insulating film formed by the method C is obtained by the method A
Has a higher relative dielectric constant than the insulating film formed by the method. Regarding the crack-resistant film thickness, the insulating film formed by the method C is smaller than the insulating film formed by the method A.
It was found to be improved about 1.6 times.

In order to obtain an insulating film having the same film quality as that of this embodiment by the method B or the method C, it is necessary to lengthen the irradiation time or increase the irradiation amount. In this case, the processing time is prolonged, the production efficiency is reduced, the insulating film having a low dielectric constant is lost due to excessive electron beam irradiation, or the crosslinking reaction of the precursor is not sufficiently achieved, and a desired film quality is obtained. It was found that an insulating film having the same could not be obtained.

In the present embodiment, the method B and the method C are combined well, that is, the heat treatment and the electron beam irradiation treatment are used in combination, and the pressure is changed in two stages, so that the low dielectric constant and the excellent resistance can be obtained. An insulating film having cracking properties was obtained.

Here, a change in the film structure of each insulating film formed by the present embodiment and the above methods AC will be considered.

FIG. 3 shows Fourier Transform Infrared Spectroscopy (FT-IR) of the insulating film (polymethylsiloxane film) formed by each method.
meter). In FIG. 3, the spectra of the three insulating films are vertically arranged for easy comparison. FT-IR of insulating film formed by method B
The spectrum was similar to that of the insulating film formed by Method C.

FIG. 3 shows that the method and method C of the present embodiment are shown.
The insulating film formed by the method described above has a smaller S ^value around 1300 cm ^-1 than the insulating film formed by the method A.
It can be seen that the peak intensity of the i-CH ₃ bond is small. This indicates that in the case of the method and method C of the present embodiment, the bond between the CH ₃ group in the molecule and the main chain was broken by electron beam irradiation.

The insulating film formed by the method A is
Around the wave numbers 1050 cm ^-1 and 1150 cm ^-1 , S
It is understood that the separation of the peak intensity of the i-O bond is remarkable. This indicates that there is a linear Si—O bond. On the other hand, in the insulating film formed by the method and the method C of the present embodiment, the separation of the peak intensity of the Si—O bond is gentle. This indicates that the linear bond was broken and a complex Si—O bond was formed.

Further, the insulating film formed by the method C has an H ₂ O bond near the wave number of 3500 cm ⁻¹ and a wave number of 9
Although a large peak due to the Si—OH bond appears around 80 cm ⁻¹ , the insulating film formed by the method and the method A of the present embodiment has almost no peak near the wave number.

From these facts, it is considered that in the case of the method C, a sufficient dehydration reaction is not performed, and a large amount of Si—OH bonds and H ₂ O remain in the insulating film.

That is, in the method C, CH near the surface of the film is used.
It is probable that although the cutting of ₃ was accelerated by electron beam irradiation and a sufficient dehydration reaction was performed, a sufficient dehydration reaction was not performed on the whole film, so that a low dielectric constant could not be obtained. On the other hand, it is considered that the crack-resistant film thickness was improved by the formation of a strong network near the surface by electron beam irradiation.

On the other hand, in the insulating film formed by the method of this embodiment, no peak due to the H ₂ O bond near the wavelength of 3500 cm ^{−1 and} no Si—OH bond near the wavelength of 980 cm ⁻¹ is observed. That is, by simultaneously performing the heat treatment at the time of the electron beam irradiation and changing the pressure, the C
The bond between the H ₃ group and the main chain is broken to form a dangling bond, and the dehydration reaction effectively occurs by heat treatment. Combine with This is considered to be the reason that the method of the present embodiment formed a strong network having a low dielectric constant and a sufficient crack resistance.

The present inventors have set forth the method, method A of the present embodiment.
And analyzing each of the insulating films formed by the method C by FT-IR, and assuming that the spectral intensity area of the Si—O bond is 1, Si—C
H ₃ bond spectral intensity area, Si—OH bond and H ₂
The respective ratios of the spectral intensity areas of the sum of O and O were examined. Table 2 shows the results.

[0090]

[Table 2]

A semiconductor device having an insulating film obtained by the method of the present invention can be generally expressed as follows.
That is, the semiconductor device according to the present invention includes a substrate and an organic silicon oxide film provided on the substrate, and when the organic silicon oxide film is analyzed by Fourier transform infrared spectroscopy, the ratio of the spectral intensity area of Si-CH ₃ bond with respect to the spectral intensity area of -O bonds 0.01 to 0.03, the spectral intensity area of H ₂ 0 and Si-OH bonds to the spectral intensity area of Si-O bonds Are 0.001 or less.

More specifically, the relative dielectric constant of the insulating film is 3.5 or less, and the crack-resistant film thickness of the insulating film is 1.5.
μm or more. The organic silicon oxide film is a polymethylsiloxane film. A wiring mainly composed of Cu is buried in the surface of the insulating film.

If the amount of electron beam irradiation is increased to further promote the crosslinking reaction, the spectral intensity of the Si—CH ₃ bond is further reduced, resulting in a simple silicon oxide film. Therefore, if the cross-linking reaction is further advanced, even if there is sufficient crack resistance, the insulating film may not be a low dielectric constant insulating film. According to experiments performed by the present inventors, it has been found that the spectral intensity area ratio of the Si—CH ₃ bond must be at least 0.01 or more.

As described above, by appropriately combining the method B and the method C as in the present embodiment, the molecular chain is effectively cut, re-crosslinked, and dehydrated and condensed, resulting in high mechanical strength, In addition, an insulating film having a low relative dielectric constant can be realized.

Further, as a result of examining the total number of scratches and cracks generated by the CMP process, the insulating film formed by the method of the present embodiment was reduced to about 1/10 as compared with the insulating film formed by the method A. It turned out to be.

In addition, regarding the thickness of the damage layer formed by dry etching and dry ashing,
It was found that the insulating film formed in the present embodiment was reduced to about 30% as compared with the insulating film formed by the method A.

In this embodiment, the pressure and the irradiation amount are changed in the step 4. However, even if only one of them is changed, it is not possible to realize an insulating film having high mechanical strength and low relative dielectric constant. It is possible.

Further, even if only one parameter other than the pressure and the irradiation amount is changed, it is possible to realize an insulating film having high mechanical strength and low relative dielectric constant. The parameters other than the pressure and the dose are the temperature of the semiconductor substrate 1, the type of gas to which the semiconductor substrate 1 is exposed, the flow rate of the gas introduced into the reaction vessel, and the position of the semiconductor substrate 1. For example, in step 4, the temperature is changed from 400 ° C. to 200 ° C., the gas type is changed from nitrogen to argon, and the gas flow rate is 25
The same effect was obtained by changing from slm to 3 slm or changing the position of the semiconductor substrate 1 from 50 mm to 120 mm.

However, in this case, it may not be realized depending on the required mechanical strength and relative dielectric constant.
Therefore, it is generally preferable to vary a plurality of parameters. Even if a plurality of parameters other than the pressure and the irradiation amount are changed, or one of the pressure and the irradiation amount and at least one or more parameters other than the pressure and the irradiation amount are changed, the same effect as that of the present embodiment is obtained. It is possible to get.

That is, at least one of the pressure in the reaction vessel, the temperature of the semiconductor substrate, the kind of gas to which the semiconductor substrate is exposed, the flow rate of the gas introduced into the reaction vessel, the position of the semiconductor substrate, and the irradiation amount Is varied, the effect as described in the present embodiment can be obtained.

In step 4, the pressure and the irradiation amount are changed in the directions of increasing and decreasing, respectively. However, if either of them is changed in the opposite direction, the effect shown in the present embodiment may not be obtained. is there. Generally, in order to obtain a desired effect by changing a plurality of parameters, the direction of the change (increase, decrease) of the parameters is also important. In general,
The direction depends on the selected parameter, required mechanical strength, relative dielectric constant, and the like. Therefore, the direction of the parameter change is appropriately selected.

The variation range of each parameter is specifically as follows. The pressure fluctuation range is greater than 0 Torr and 400 Torr or less, and the temperature fluctuation range is 20 Torr.
The variation range of the gas type is 0 ° C. or more and 500 ° C. or less, and the variation range of the gas type is selected from a nitrogen gas having a oxygen concentration of 100 ppm or less, a rare gas, a reducing gas (eg, H ₂ ), and a mixed gas composed of at least two or more of these gases. The fluctuation range of the flow rate is greater than 0 slm and 25 slm or less, and the fluctuation range of the position is 50 m from the lower end of the electron beam generating unit that generates the electron beam.
m or more 120mm or less apart positions, fluctuation region of the dose is 10 [mu] C / cm ² · more 4μC / cm ² · sec
sec or less.

The heat treatment steps 2 and 3 may be performed in a different reaction vessel from step 4, or of course, may be performed in the same reaction vessel as step 4.

In the present embodiment, the present invention is applied to the formation of the lowermost interlayer insulating film in the multilayer wiring structure.
In addition, the same method can be applied to the formation of an interlayer insulating film in each layer.

(Second Embodiment) Next, a method for manufacturing a semiconductor device according to a second embodiment of the present invention will be described. The present embodiment is different from the first embodiment in the method of forming the interlayer insulating film 3, and the outline thereof is as follows (Step 1-5).

Step 1: A varnish is applied on the semiconductor substrate 1 by spin coating. Step 2: The semiconductor substrate 1 is subjected to a heat treatment at 80 ° C. for 1 minute. Step 3: The semiconductor substrate 1 is subjected to a heat treatment at 200 ° C. for 1 minute. Step 4: An electron beam irradiation treatment is performed while heating the semiconductor substrate 1 in a reduced-pressure nitrogen atmosphere to form the interlayer insulating film 3. Step 5: The semiconductor substrate 1 is subjected to a heat treatment at 400 ° C. for about 2 minutes.

The above forming method will be described in more detail. First, Steps 1-3 are performed as in the first embodiment.

Thereafter, about 20 slm of nitrogen is introduced into the reaction vessel, and the semiconductor substrate 1 is placed in a reduced pressure nitrogen atmosphere.
While placed on a hot plate maintained at 0 ° C,
The coating film is irradiated with an electron beam to form an interlayer insulating film 3 (polymethylsiloxane film) (Step 4).

At the time of electron beam irradiation in step 4, the present embodiment
In the state, the pressure in the reaction vessel is 10 Torr and 60 Torr.
r was varied in two stages. That is, whether to start electron beam irradiation
For about 180 seconds, the pressure in the reaction vessel is increased to 10 Torr.
And the irradiation amount is about 5 μC / cm ^Two・ Electron beam irradiation as sec
Approximately 30 seconds from the start of irradiation to the end of electron beam irradiation
During this time, the pressure inside the reaction vessel was set to 60 Torr,
About 4μC / cm^Two-Electron beam irradiation was performed as sec.

In this embodiment, in order to maintain the uniformity of the electron beam irradiation under the above conditions, a hot plate was set at a position 75 mm from the lower end of the electron beam generating section, and the electron beam irradiation was performed. .

Further, the semiconductor substrate 1 is placed on a hot plate maintained at 400 ° C. in the same reaction vessel as in Step 4, and heat-treated for about 2 minutes (Step 5). In step 5, for about 30 seconds from the start of the processing, a hot plate on which the semiconductor substrate 1 is placed is placed at a position 75 mm away from the lower end of the electron beam generating section, and the processing is performed. A hot plate on which the semiconductor substrate 1 was placed was placed at a position about 120 mm from the lower end of the electron beam generator, and heat treatment was performed.

For the same reason as in step 4 of the first embodiment, in the heat treatment of step 4, the substrate temperature is set to 200
It is desirable that the temperature is set to be higher than or equal to 500 ° C.

Further, it was effective that the heat treatment temperature in step 5 was the same as or higher than the heating temperature in step 4. Further, it was effective that the processing time in step 5 was equal to or longer than the processing time in step 4.

For the same reason as in the case of the step 4 of the first embodiment, the steps 4 and 5 of the present embodiment are desirably performed in a reduced pressure atmosphere in which the oxygen concentration is suppressed to 100 ppm or less.

The characteristics of the polymethylsiloxane film formed by the above-described method were the same as those shown in the first embodiment.

Further, it has been confirmed that the heat treatment of Step 5 can recover the damage that has entered the gate insulating film of the semiconductor element due to the irradiation of the electron beam, thereby improving the characteristics of the semiconductor device such as the leak current and the threshold voltage.

In step 5, the above-described effect was obtained regardless of the type of gas to which the substrate to be processed was exposed was N ₂ , Ar, or forming gas (mixed gas of N ₂ and H ₂ ). In the case of forming gas, compared to N ₂ and Ar
About 1.5 times the effect was obtained.

In this embodiment, the position (gap) of the semiconductor substrate 1 is changed in the heat treatment step 5 (post-process), but at least one or more other parameters may be changed. Other parameters are the pressure in the reaction vessel, the temperature of the semiconductor substrate 1, the type of gas to which the semiconductor substrate 1 is exposed, and the flow rate of the gas introduced into the reaction vessel. Further, at least two positions including the position of the semiconductor substrate 1
One or more parameters may be varied. The variable range of the parameters in step 5 is specifically described in step 4 above.
Are the same as those in The heat treatment in the pre-process is performed in the reaction vessel in which the electron beam irradiation process is performed, and is performed continuously with the electron beam irradiation process, similarly to the heat treatment in the post-process.

The direction in which the parameter fluctuates may be a direction in which the temperature increases, and a direction in which the pressure, the flow rate and the gap increase and decrease. It is realistic that the gas species fluctuates from argon or nitrogen to a mixed gas thereof.

In this embodiment, the parameters are changed in the heat treatment in the post-process. However, the parameters may be changed in the heat treatment in the pre-process performed continuously with the electron beam irradiation process. The heat treatment in the previous step indicates the heat treatment in step 3. In this case, the heat treatment of step 2 can be absorbed by the heat treatment of step 3, and step 2 can be omitted. In this case, the directions in which the parameters fluctuate are the same as those in the subsequent steps with respect to temperature, pressure, flow rate and gap. The gas type is a variation from nitrogen to argon or from argon to nitrogen. Further, parameters may be varied in the heat treatment in the pre-process and the post-process.

(Third Embodiment) Next, a method of manufacturing a semiconductor device according to a third embodiment of the present invention will be described. The present embodiment is different from the first embodiment in the method of forming the interlayer insulating film 3, and the outline thereof is as follows (Step 1-2).

Step 1: A varnish is applied on the semiconductor substrate 1 by spin coating.

Step 2: An electron beam irradiation process is performed while heating the semiconductor substrate 1 in a nitrogen atmosphere under reduced pressure to form an interlayer insulating film 3.

The above forming method will be described in more detail. First, similarly to the first embodiment, Step 1 is performed to form a coating film.

Next, the above-mentioned semiconductor substrate is placed on a hot plate maintained at 400 ° C. in a nitrogen atmosphere under reduced pressure, and the coating film is irradiated with an electron beam to form an interlayer insulating film 3 (Step 2). ). The electron beam irradiation is performed with an electron beam energy of 6
kev, the total irradiation amount: 500 μC / cm ² .

Here, for the same reason as in the case of the step 4 of the first embodiment, the step 2 is performed when the oxygen concentration is 100 ppm.
It is desirable to have a reduced-pressure atmosphere suppressed to the following.

Further, for the same reason as in step 4 of the first embodiment, it is desirable to set the substrate temperature in the heat treatment in step 2 to 200 ° C. or more and 500 ° C. or less.

The same effect as that of the first embodiment was obtained by the polymethylsiloxane film formed by the method of the present embodiment. In addition, the present embodiment is smaller than the first embodiment in the number of steps by two, and is therefore superior to the first embodiment in terms of production efficiency. Note that, in the present embodiment, at least one or more parameters are varied as in the first embodiment, and the same effect as in the first embodiment is obtained. For example, the substrate temperature can be changed from 200 ° C. to 400 ° C.

(Fourth Embodiment) Next, a method of manufacturing a semiconductor device according to a fourth embodiment of the present invention will be described. This embodiment is different from the first embodiment in the method of forming the interlayer insulating film 3, and the outline thereof is as follows (Step 1-3).

Step 1: A varnish is applied on the semiconductor substrate 1 by spin coating. Step 2: An electron beam irradiation treatment is performed while heating the semiconductor substrate 1 in a nitrogen atmosphere under the atmospheric pressure (780 Torr) to form the interlayer insulating film 3. Step 3: The semiconductor substrate 1 is subjected to a heat treatment at 400 ° C. for about 2 minutes.

The above forming method will be described in more detail. First, similarly to the first embodiment, Step 1 is performed to form a coating film. (Step 1).

Next, the semiconductor substrate 1 is placed on a hot plate maintained at 200 ° C. in a nitrogen atmosphere under atmospheric pressure, and the coating film is irradiated with an electron beam to form an interlayer insulating film ( Step 2). The electron beam irradiation is performed using an electron beam energy:
The test was performed under the conditions of 6 keV and an irradiation amount of 500 μC / cm ² .

For the same reason as in step 4 of the first embodiment, the heating in step 2 is performed by setting the substrate temperature to 200 ° C.
It is desirable that the temperature is not less than 500 ° C. Further, for the same reason as in the case of step 4 of the first embodiment, step 2
Is preferably performed in an atmosphere in which the oxygen concentration is suppressed to 100 ppm or less.

According to the experiments by the present inventors, step 3
It has been found that it is more effective to set the temperature of the heat treatment at the same as or higher than the temperature of the heat treatment at the step 2. In addition, it was found that the time of the heat treatment in the step 3 was almost the same as or longer than the time of the heat treatment in the step 2. Further, for the same reason as in the case of the step 4 of the first embodiment, the step 3 is performed when the oxygen concentration is 100%.
It is desirable to carry out in an atmospheric pressure atmosphere or a reduced pressure atmosphere which is suppressed to ppm or less.

As the characteristics of the polymethylsiloxane film formed by the method of this embodiment, the same effects as those of the first embodiment were obtained.

Further, as in the second embodiment, the heat treatment in step 3 can recover the damage of the element and the like caused by the electron beam irradiation, thereby improving the characteristics such as the leak current and the threshold voltage of the MOS element. it can. Also, the present embodiment has two fewer steps than the second embodiment,
In terms of production efficiency, it is superior to the second embodiment.
In this embodiment, the same effects as in the first embodiment can be obtained by changing at least one parameter in the same manner as in the first embodiment. For example, the substrate temperature can be changed from 200 ° C. to 400 ° C.

(Fifth Embodiment) FIG. 4 shows a fifth embodiment of the present invention.
FIG. 14 is a cross-sectional view showing a manufacturing step of the semiconductor device according to the embodiment.

First, as shown in FIG. 4A, a base insulating film 102 is formed on a surface of a semiconductor substrate 101. Here, a TEOS film is used as the base insulating film 102.
Subsequently, a wiring groove having a desired size and shape is formed at a predetermined position on the front surface side of the base insulating film 102, and thereafter, the barrier metal 103 and Cu are mainly contained inside the wiring groove by a known CMP process. Forming a Cu wiring 104, a base insulating film 102, a barrier metal 10
3 and the surface of the Cu wiring 104 are flattened.

Next, as shown in FIG. 4B, the planarized base insulating film 102, barrier metal 103 and Cu
On the surface of the wiring 104, a silicon nitride film 105 as a barrier insulating film is formed.

Next, as shown in FIG. 4C, an interlayer insulating film 106 having a low dielectric constant is provided on the silicon nitride film 105. Here, a polymethylsiloxane film is used as the interlayer insulating film 106 having a low dielectric constant.

Hereinafter, the step of forming the polymethylsiloxane film will be described in detail by dividing into steps 1-4.

In the following description, as shown in FIG. 4B, a structure in which the semiconductor substrate 101 is formed up to the SiN layer 105 is referred to as a first-layer semiconductor substrate. A desired semiconductor device 109 can be obtained by sequentially performing the following steps 1-4 described below on the first layer semiconductor substrate 108.

Step 1: A liquid material (not shown) called a varnish obtained by dissolving a polymethylsiloxane film material or a polymethylsiloxane as a precursor thereof in a solvent is supplied onto the surface of the silicon nitride film 105. As a method of supplying the varnish, in the present embodiment,
A coating method capable of uniformly supplying a varnish with a substantially uniform thickness so that a high-quality polymethylsiloxane film is formed is employed. Specifically, this varnish application operation is to apply a varnish onto the surface of the silicon nitride film 105 by a spin coat method, which is a kind of application method, using a coater (not shown) as an application apparatus.

Step 2: The first layer semiconductor substrate 108 is
As shown in (c), the silicon nitride film 5 coated with the varnish is placed on a hot plate 107 (heating device) as a temperature control device with the varnish applied upward. Thereafter, the temperature of the hot plate 107 is adjusted so that the temperature of the varnish is maintained at about 80 ° C., the varnish is heated together with the first layer semiconductor substrate 108, and this state is maintained for about 1 minute. Thereby, the varnish is subjected to the first heat treatment.

Step 3: With the first layer semiconductor substrate 108 placed on the hot plate 107, the hot plate 107 is maintained so that the temperature of the varnish is maintained at about 200 ° C.
The varnish is heated together with the first layer semiconductor substrate 108, and this state is maintained for about 1 minute. Thus, the varnish is subjected to a second heat treatment.

By the heat treatment in the second and third steps, the solvent contained in the varnish is removed by evaporation.
A varnish (coating film) is fixed (fixed) on the silicon nitride film 105.

According to the experiment conducted by the present inventors, the heating method of increasing the temperature of the varnish stepwise as in Steps 2 and 3 allows the polymethylsiloxane film in the varnish to be formed. It has been clarified that components (for example, a solvent) other than the main component, polymethylsiloxane, can be efficiently and almost completely volatilized, and the coating film can be effectively fixed.

Step 4: With the first layer semiconductor substrate 108 placed on the hot plate 107, the varnish and the polymethylsiloxane film formed based on the varnish are decompressed to about 10 Torr so as not to be oxidized. It is placed under a reduced pressure atmosphere. At the same time, the atmosphere in which the first layer semiconductor substrate 108 is arranged is filled with a gas mainly composed of a reducing H ₂ gas. The H ₂ gas cleans the surface of the Cu wiring 104 and suppresses oxidation of the surface when performing an electron beam irradiation operation described later.

In this state, the temperature of the varnish is about 40.
The temperature of the hot plate 107 is adjusted so as to be maintained at 0 ° C., the varnish is heated together with the first layer semiconductor substrate 108, and an electron beam irradiation device (not shown) as shown by an arrow in FIG. Irradiation (acceleration) toward varnish
Energy is about 10 keV, total irradiation amount is about 500 μC /
Irradiate an electron beam of cm ² .

At this time, the heating state and the electron beam irradiation state are maintained for about 5 minutes. Thus, a polymethylsiloxane film is formed on the surface of the silicon nitride film 105, in other words, on the uppermost layer of the first layer semiconductor substrate.

As described above, of the steps 2-4,
The varnish is irradiated with an electron beam while subjecting the varnish to heat treatment only in the final step, step 4.

The reason is that when the varnish not fixed on the silicon nitride film 105 is irradiated with an electron beam, even components other than polymethylsiloxane, such as a solvent, contained in the varnish are deteriorated. This is to prevent the formation of a low dielectric constant interlayer insulating film having undesired characteristics due to altered components. That is, it is to obtain a polymethylsiloxane film as a low dielectric constant interlayer insulating film 106 having desired characteristics.

According to the experiment performed by the present inventors, Step 4
In irradiating the varnish with an electron beam, the temperature of the varnish is 200 ° C. or more and 500 ° C. or less, preferably about 380-4.
By performing a heat treatment at a substantially constant temperature within a range of about 00 ° C., particularly about 400 ° C., the semiconductor device 10
9 showed that a high-quality polymethylsiloxane film capable of exhibiting practically appropriate operation performance could be formed.

According to the experiment performed by the present inventors,
In step 4, the total amount of electron beam irradiation to the varnish is
By irradiating the electron beam while setting it to be a substantially constant value of about 500 μC / cm ² or more, preferably about 500 μC / cm ² , a high quality semiconductor device 109 can exhibit practically appropriate operation performance. It became clear that a polymethylsiloxane film could be formed.

Similarly, according to an experiment conducted by the present inventors, the acceleration energy of the electron beam irradiated to the varnish in step 4 is set to a substantially constant value within a range of about 1 keV to 15 keV, preferably about 10 keV. It has been clarified that the semiconductor device 109 can form a high-quality polymethylsiloxane film capable of exhibiting practically appropriate operation performance by performing electron beam irradiation with such settings.

Further, according to an experiment conducted by the present inventors, when the varnish is irradiated with an electron beam while being subjected to a heat treatment in step 4, the varnish is subjected to a predetermined range in a gas having a predetermined reducing property. It has been clarified that the semiconductor device 109 can form a high-quality polymethylsiloxane film capable of exhibiting practically appropriate operation performance by disposing the semiconductor device 109 in a reduced-pressure atmosphere.

Particularly, in the above H ₂ gas, about 0.1
It has been found that the semiconductor device 109 can form an extremely high-quality polymethylsiloxane film that can exhibit extremely good operation performance in practical use by disposing the varnish in an atmosphere set to a reduced pressure value of Torr.

After the above-described Step 4 was completed, when the obtained semiconductor device 109 was observed using an optical microscope (not shown), no oxidation of the surface of the Cu wiring 104 was observed.

During the process 1-4 and after the completion of these processes, the base insulating film 10
2. Peeling of the barrier metal 103, the Cu wiring 104, the silicon nitride film 105, and the interlayer insulating film 106 (polymethylsiloxane film) was not observed at all.

When the resistivity of the Cu wiring 104 was measured, the size was substantially the same before and after forming the polymethylsiloxane film as the interlayer insulating film 106.

As described above, according to the present embodiment, by using both the heating operation and the electron beam irradiation operation, the steps 1-4 can be completed in a short time of only about 7 minutes in total.

That is, according to the present embodiment, in the process of forming an insulating film only by a heat treatment using a hot plate according to the conventional technique, it takes about 30 minutes to 1 hour for solvent volatilization and precursor evaporation. Can significantly reduce the film forming process associated with the crosslinking reaction.

Further, according to the present embodiment, by using the heating operation and the electron beam irradiation operation together, the film baking temperature in the step 1-4 is set to, for example, 400 ° C. as described above, or the upper limit even if it is higher. Can be suppressed to 500 ° C. or less.

That is, according to the present embodiment, in the process of forming an insulating film only by a heat treatment using a hot plate according to the prior art, a film baking process requiring an extremely high film baking temperature of 500 ° C. or more is required. The film firing temperature in the final step can be lowered.

Therefore, according to the present embodiment, by using both the heating operation and the electron beam irradiation operation, the interlayer insulating film 106 or the Cu wiring 104 is hardly exposed to unnecessary stimulus. The insulating film 106 can be formed. Thereby, the Cu wiring 104 in the film forming process is formed.
Is suppressed, and peeling at the interface between the Cu wiring 104 and the silicon nitride film 105 is suppressed.

By irradiating the varnish with an electron beam in an atmosphere of reduced-pressure H ₂ gas having a reducing property, the oxidation of the surface of the Cu wiring 104 when the interlayer insulating film 106 is formed is suppressed. As a result, the resistance value of the Cu wiring 4 can be maintained in a good low state. The reducing gas may be a gas other than the H ₂ gas. Generally, any material can be used as long as it can prevent oxidation of the wiring (here, the Cu wiring 4) and does not degrade the quality of the film to be formed (here, the interlayer insulating film 106).

Therefore, according to the present embodiment, the electrical performance (quality) of the semiconductor device 109 such as the capacitance between wirings can be improved, and the semiconductor device 109 can be manufactured in a short time.
As a result, the yield of the semiconductor device 109 is improved, and the production efficiency of the semiconductor device 109 is increased.

According to the present embodiment, the interlayer insulating film 1
06, even if a polymethylsiloxane film, which is a low-dielectric-constant insulating film, can be formed in a short time without deteriorating its performance and maintaining a good state, the relative dielectric constant of the semiconductor device 109 can be reduced. It can be maintained in a good low state.

That is, according to the present embodiment, the wiring capacitance of the semiconductor device 109 can be reduced, and the product of the wiring resistance and the line capacitance can be reduced. Thereby, the semiconductor device 10
9. The operating speed of various semiconductor devices using the semiconductor device 109 can be improved.

When a semiconductor device in which a plurality of wiring layers are stacked is desired, the first
The layers such as the barrier metal 103, the Cu wiring 104, the silicon nitride film 105, and the interlayer insulating film 106 may be repeatedly formed by the same method as described above via the base insulating film 102.

As described above, even if a plurality of wiring layers are formed,
There is almost no risk of deteriorating the electrical performance such as the capacitance between wirings. Therefore, a semiconductor device having a high processing capability, and various semiconductor devices having a high processing capability using the semiconductor device can be produced.

(Sixth Embodiment) FIG. 5 shows a sixth embodiment of the present invention.
FIG. 14 is a cross-sectional view showing a manufacturing step of the semiconductor device according to the embodiment. This embodiment is different from the fifth embodiment in that a polymethylsiloxane film is used as the base insulating film 102.

First, as shown in FIG. 5A, a base insulating film 102 is formed on a surface of a semiconductor substrate 101. Here, a polymethylsiloxane film is used as the base insulating film 102.

Hereinafter, the step of forming the polymethylsiloxane film will be described in detail by dividing it into steps 1-4.

Step 1: A varnish obtained by dissolving a polymethylsiloxane film material or a polymethylsiloxane as a precursor thereof in a solvent is applied on the surface of the semiconductor substrate 1. The method of applying the varnish is the same as, for example, the step 1 of the fifth embodiment.

Step 2: As shown in FIG. 5A, the semiconductor substrate 1 is placed on the hot plate 107 with its varnish applied surface facing upward. Thereafter, the temperature of the hot plate 107 is adjusted so that the temperature of the varnish is maintained at about 80 ° C., the varnish is heated together with the semiconductor substrate 1, and this state is maintained for about 1 minute. Thereby, the varnish is subjected to the first heat treatment.

Step 3: With the semiconductor substrate 101 placed on the hot plate 107, the temperature of the varnish is reduced to about 2
The temperature of the hot plate 107 is adjusted so as to be maintained at 00 ° C., and the varnish is heated together with the semiconductor substrate 101, and this state is maintained for about one minute. Thus, the varnish is subjected to a second heat treatment.

Step 4: With the semiconductor substrate 101 placed on the hot plate 107, the temperature of the varnish is set to about 4
The temperature of the hot plate 107 is adjusted so as to be maintained at 00 ° C., and the varnish is heated together with the semiconductor substrate 101, and this state is maintained for about 30 minutes. Thus, the varnish is subjected to a third heat treatment.

The solvent contained in the varnish applied on the semiconductor substrate 1 in step 1 is volatilized (evaporated) and removed by the heat treatment in step 2-4 described above. As a result, the varnish (coating film) is fixed on the semiconductor substrate 101.

After the above-described steps 1-4, a wiring groove is formed in the surface of the underlying insulating film 102 and the barrier metal 103 and the Cu wiring
4 is obtained, and the structure shown in FIG. 5A is obtained.

Next, as shown in FIG. 5B, the base insulating film 102, the barrier metal 103, and the Cu wiring 104
A silicon nitride film 105 is formed on the surface of the substrate, and a first layer semiconductor substrate 108 is formed.

Thereafter, as shown in FIG. 5C, the interlayer insulating film 106 (polymethylsiloxane film) is formed by using a silicon nitride film by heating and electron beam irradiation in a similar manner to the fifth embodiment. 105 on the surface of the semiconductor device 10
9 is formed.

The semiconductor device 109 obtained as described above
Was observed using an optical microscope, and Cu wiring 104
No oxidation of the surface was observed.

Also, while performing Steps 2-4, while performing each of the following steps up to the formation of the interlayer insulating film 106, and after completing these steps, the base insulating film 102 (Polymethylsiloxane film), barrier metal 103, Cu wiring 104, silicon nitride film 1
05, and peeling of the interlayer insulating film 106 (polymethylsiloxane film) were not observed at all.

When the resistance value of the Cu wiring 104 was measured, the size was substantially the same before and after the formation of the interlayer insulating film 106. Further, the interlayer insulating film 106
On the other hand, when the CMP process was performed, the interlayer insulating film 106 did not peel off.

In the present embodiment, the same effects as in the fifth embodiment can be obtained. Further, according to the present embodiment, since the polymethylsiloxane film is used as the base insulating film 102, the relative dielectric constant of the semiconductor device 109 can be further reduced. That is, the wiring capacitance of the semiconductor device 109 can be further reduced, and the product of the wiring resistance and the line capacitance can be further reduced. Accordingly, the operation speed of the semiconductor device 109 and, eventually, various devices using the semiconductor device 109 can be further improved.

(Seventh Embodiment) Next, a method of manufacturing a semiconductor device according to a seventh embodiment of the present invention will be described. Since the cross-sectional view showing the manufacturing process of this embodiment is the same as that of the sixth embodiment, the manufacturing method of this embodiment will be described with reference to FIG. This embodiment is different from the fifth embodiment in that a polymethylsiloxane film is used as the base insulating film 102, and the polymethylsiloxane film is formed by using both a heating operation and an electron beam irradiation operation.

As shown in FIG. 5A, the semiconductor substrate 10
The base insulating film 102 is formed on the surface of the substrate 1. In this embodiment, a polymethylsiloxane film is formed as the base insulating film 102. The method of forming the polymethylsiloxane film is the same as that of the interlayer insulating film 10 described in the fifth embodiment.
Similarly to the method of forming the polymethylsiloxane film of No. 5, the film is formed by using both the heating operation and the electron beam irradiation operation.

Subsequently, a wiring groove having a desired size and shape is formed at a predetermined position on the front surface side of the base insulating film 102, and thereafter, the inside of the wiring groove is formed into a barrier metal 103 and a well by a well-known CMP process. The surface of the base insulating film 102 (polymethylsiloxane film), the barrier metal 103, and the surface of the Cu wiring 104 are flattened while filling with the Cu wiring 104.

Next, as shown in FIG. 5B, a silicon nitride film 105 is formed on the surfaces of the base insulating film 102, the barrier metal 103 and the Cu wiring 104, and a first layer semiconductor substrate 108 is formed.

Next, as shown in FIG. 5C, a polymethylsiloxane film as the low-dielectric-constant interlayer insulating film 106 is heated and irradiated with an electron beam in the same manner as in the fifth embodiment. Together, they are formed on the surface of the silicon nitride film 105 to form the semiconductor device 109.

After the formation of the polymethylsiloxane film as the interlayer insulating film 106 described above was completed, the obtained semiconductor device 109 was observed with an optical microscope. As a result, oxidation of the surface of the Cu wiring 104 was observed. Did not.

[0193] Also, during the execution of each of the above steps and after the completion of each of the above steps, the underlying insulating film 102 is formed.
(Polymethylsiloxane film), barrier metal 103, C
Peeling of the u wiring 104, the silicon nitride film 105, and the interlayer insulating film 106 (polymethylsiloxane film) was not observed at all. When the resistance value of the Cu wiring 104 was measured, the size was substantially the same before and after the formation of the interlayer insulating film 106. Further, when the polymethylsiloxane film was subjected to the CMP method, the peeling did not occur.

According to the present embodiment, by forming the polymethylsiloxane film as the base insulating film 102 by using both the heating operation and the electron beam irradiation, the polymethylsiloxane film having a lower dielectric constant than the sixth embodiment can be obtained. A methylsiloxane film can be formed. Thus, the wiring capacitance of the semiconductor device 109 can be further reduced, and the product of the wiring resistance and the line capacitance can be further reduced. As a result, the operation speed of the semiconductor device 109, and furthermore, various devices using the semiconductor device 109 can be further improved.

Further, according to the present embodiment, the base insulating film 1
By forming the polymethylsiloxane film 02 by using both the heating operation and the electron beam irradiation, the above-mentioned polymethylsiloxane film, and furthermore, the semiconductor device 109 including the polymethylsiloxane film can be formed in a short time. Therefore, the semiconductor device 109 and, consequently, the semiconductor device 10
9 can improve the production efficiency of various devices.

As described above, the method for fabricating a semiconductor device according to the fifth to seventh embodiments relates to a method for fabricating a semiconductor device having Cu wiring, and particularly relates to a method for fabricating a low dielectric constant interlayer insulating film to be subjected to electron beam irradiation. It includes a forming step. for that reason,
The method for manufacturing a semiconductor device according to the fifth to seventh embodiments can be referred to as Cu integration using an EB-cured SOG film.

In the fifth to seventh embodiments, as in the first embodiment, the same effects as in the first embodiment can be obtained by changing at least one parameter.

(Eighth Embodiment) According to the study of the present inventors, the polymethylsiloxane film formed by heating and electron beam irradiation as in the above embodiment can be obtained by applying light from the outside. It was found to emit fluorescence. The reason is that by performing heating work and electron beam irradiation work at the same time,
This is presumably because CC bonds as formed in the structure of the organic resin film were formed in the polymethylsiloxane film.

In the present embodiment, a method for evaluating the uniformity of the in-plane cure of the polymethylsiloxane film using such properties of the polymethylsiloxane film will be described.

First, steps 1-4 of the first embodiment are performed to form a 1 μm-thick polymethylsiloxane film.
The film forming conditions are the same except that the electron beam energy in step 4 is 6 keV.

Next, Ar ⁺ laser of 514.5 nm is irradiated to 94 places on the polymethylsiloxane film. At this time, the intensity of the fluorescence emitted from the above-mentioned 94 points of the polymethylsiloxane film is measured. FIG. 6 shows the measurement results. Then, the uniformity of the in-plane cure of the polymethylsiloxane film is evaluated from the variation in the intensity of the fluorescence. The smaller the variation in the intensity of the fluorescent light, the higher the uniformity. Conversely, the larger the variation in the intensity of the fluorescent light, the lower the uniformity.

(Ninth Embodiment) This embodiment is different from the eighth embodiment in that the thickness distribution of the polymethylsiloxane film is evaluated from the intensity distribution of the fluorescence emitted from the polymethylsiloxane film. is there.

First, Steps 1-4 of the first embodiment are performed to form a 1 μm-thick polymethylsiloxane film.
The electron beam energy in step 4 is the same as that of the eighth embodiment.

Next, Ar ⁺ laser of 514.5 nm was irradiated to 94 places on the polymethylsiloxane film,
The intensity of the fluorescence emitted from the above-mentioned 94 points of the polymethylsiloxane film is measured.

Since there is a relationship between the intensity of the fluorescence emitted from the polymethylsiloxane film and the shrinkage of the polymethylsiloxane film, the relationship is determined in advance. An example is shown in FIG. The actual film thickness of the portion emitting the fluorescence is the designed film thickness of the polymethylsiloxane film (here, 1 μm).
m) and the shrink rate corresponding to the intensity of the fluorescence at that portion.

Therefore, the thickness distribution of the polymethylsiloxane film can be evaluated by calculating the product of the designed film thickness and the shrinkage ratio corresponding to the intensity of the fluorescent light at each of the 94 points. Become.

(Tenth Embodiment) This embodiment is different from the ninth embodiment in that the thickness distribution of the polymethylsiloxane film is evaluated during the formation of the polymethylsiloxane film.

First, step 1-3 of the first embodiment is performed.

Next, while performing Step 4 of the first embodiment, 94+ portions of the polymethylsiloxane film being formed are irradiated with Ar ⁺ laser of 514.5 nm.
Then, the film thickness distribution of the polymethylsiloxane film during film formation is evaluated by the method described in the ninth embodiment. That is, a polymethylsiloxane film is formed while monitoring the film thickness. As a result of monitoring, if the film thickness distribution does not become the predetermined distribution, for example, the film forming conditions are changed during the film formation or the film formation is stopped.

(Eleventh Embodiment) In this embodiment, a method of utilizing light emission from a polymethylsiloxane film for alignment will be described.

First, Step 1-3 of the first embodiment is performed.

Next, under a reduced pressure atmosphere, the semiconductor substrate is
Heat for 30 minutes on a 0 ° C. hot plate. At this time, as shown in FIG. 8, an electron beam light shielding mask 26 is arranged above the semiconductor substrate 1 and only the alignment mark portion at the peripheral edge of the polymethylsiloxane film 27 formed on the uppermost layer of the semiconductor substrate 1 is formed. Is irradiated with an electron beam 24. The irradiation condition at this time is, for example, electron beam energy: 6 ke
V, total irradiation dose: 500 μC / cm ² . The first
Similarly to the above embodiment, when performing the electron beam irradiation processing while performing the heating processing, at least one or more parameters may be changed.

Next, a method for aligning the semiconductor substrate 1 (wafer) after the step of forming the polymethylsiloxane film will be described. As shown in FIG. 8, an Ar ⁺ laser of 514.5 nm is irradiated along the periphery of the polymethylsiloxane film. At this time, when the alignment mark portion is irradiated with the Ar ⁺ laser, the polymethylsiloxane film emits fluorescence. Therefore, the position of the semiconductor substrate 1 (wafer) is determined by measuring the location where the fluorescence is emitted, and the alignment can be performed.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, in the above embodiment, a polymethylsiloxane film is given as an example of the insulating film, but the present invention can be applied to the formation of other insulating films. For example, a coated organic silicon oxide film (SOG) having a Si—C bond (generally a Si—CH ₃ bond) in the film, an organic film, or a solution that is cured by heat or the like to be insulated. Is raised. From another viewpoint, a combined use of the heating operation and the electron beam irradiation operation allows a film forming reaction to proceed in a short time, and any insulating film containing a material whose quality does not deteriorate can be used. .

In the above embodiment, the spin coating method is used as the varnish coating method, but another coating method such as a nozzle scan coating method may be used. When forming the insulating film using a coating method, instead of evaporating the solvent by gradually increasing the temperature of the varnish, the varnish is placed in a predetermined reduced-pressure atmosphere to volatilize the solvent, thereby forming the insulating film. May be fixed to the substrate.

Further, in the above embodiment, an interlayer insulating film having a low dielectric constant is taken as an example of the insulating film.
Other insulating films such as a gate insulating film are also possible.

Furthermore, the sequence of the method for forming the coating film is not limited to the sequence described in the above embodiment, and the order of performing the heat treatment + electron beam irradiation treatment step, the heat treatment In addition, the number of times of performing the electron beam irradiation treatment and the conditions of the heat treatment and the electron beam irradiation treatment can be appropriately changed. Conditions for electron beam irradiation include, for example, electron beam energy, irradiation dose, atmosphere, and substrate temperature during irradiation.

In addition, various set values such as the heating temperature and the heating time of the varnish, the reduced pressure value of the atmosphere, and the like can be similarly appropriately changed. That is, the above-mentioned various set values may be set in various combinations depending on the manufacturing environment as long as the performance of the semiconductor device can reach a desired level.

Further, the material used for the wiring may be other than Cu. It is sufficient that the resistivity of the wiring is low enough not to hinder the operation speed of the semiconductor device.

Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements described in the embodiment, if the problem described in the section of the problem to be solved by the invention can be solved, the constituent Can be extracted as an invention.

In addition, various modifications can be made without departing from the spirit of the present invention.

[0222]

As described above in detail, according to the present invention, a method of manufacturing a semiconductor device having an insulating film having a low dielectric constant and sufficient mechanical strength can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a manufacturing process of a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a schematic view showing an electron beam irradiation apparatus used in an embodiment of the present invention.

FIG. 3 shows an embodiment of the present invention and a comparative example (methods AC).
Showing the FT-IR spectrum of each insulating film formed by the method shown in FIG.

FIG. 4 is a sectional view showing a manufacturing process of a semiconductor device according to a fifth embodiment of the present invention.

FIG. 5 is a sectional view showing a manufacturing process of the semiconductor device according to the sixth and seventh embodiments of the present invention;

FIG. 6 is a diagram showing a measurement result of the intensity of fluorescence emitted from a portion of the polymethylsiloxane film irradiated with an Ar ⁺ laser.

FIG. 7 is a diagram showing an example of a relationship between the intensity of fluorescence emitted from a polymethylsiloxane film and the shrinkage of the polymethylsiloxane film.

FIG. 8 is a schematic view showing an electron beam irradiation apparatus used in an eleventh embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Semiconductor substrate 2 ... Base insulating film 3 ... Interlayer insulating film 4 ... Barrier metal 5 ... Metal wiring 21 ... Processing chamber 22 ... Electron beam generating part 23 ... Partition wall 24 ... Electron beam 25 ... Hot plate 26 ... Electron beam shielding mask 27 ... polymethylsiloxane film 101 ... semiconductor substrate 102 ... underlying insulating film 103 ... barrier metal 104 ... Cu wiring 105 ... silicon nitride film 106 ... interlayer insulating film 107 ... hot plate 108 ... first layer semiconductor substrate 109 ... semiconductor device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Rinhei Nakata 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside the Toshiba Yokohama Office (72) Inventor Masahiko Hasunuma 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Inside Toshiba Yokohama Office (72) Inventor Hidefumi Miyajima 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside the Toshiba Yokohama Office (72) Katsumi Okumura 1-1-1, Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa (72) Nobuo Hayasaka, No. 8 Shinsugitacho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 5F033 HH11 MM01 MM13 QQ48 RR04 RR06 RR23 RR25 SS04 SS22 WW01 WW03 WW04 WW05 WW06 WW07 XX17 XX24 5F058 AA02 AA10 AC03 AF04 AG01 AG10 AH02

Claims (16)

[Claims] A step of preparing a substrate to be processed; and a step of forming an insulating film on the substrate to be processed. The step of forming the insulating film includes forming the insulating film on the substrate to be processed. A step of applying a precursor of a constituent substance or an insulating film raw material containing the substance, and irradiating the insulating film raw material with an electron beam while heating the substrate to be processed in a reaction vessel;
A step of curing the insulating film raw material, wherein the pressure in the reaction vessel, the temperature of the processing target substrate, and the processing target substrate are exposed when the insulating film raw material is irradiated with the electron beam. Varying at least one of a gas type, a flow rate of a gas introduced into the reaction vessel, a position of the substrate to be processed, and an amount of electrons incident on the substrate to be processed per unit time. A method for manufacturing a semiconductor device, comprising: 2. The method of manufacturing a semiconductor device according to claim 1, wherein the pressure in the reaction vessel is varied within a range of more than 0 Torr and not more than 400 Torr. 3. The temperature of the substrate to be processed is 200 ° C. or more and 50 ° C. or more.
2. The method according to claim 1, wherein the temperature is varied within a range of 0 ° C. or less.
13. The method for manufacturing a semiconductor device according to item 5. 4. The method according to claim 1, wherein a change in the type of gas to which the substrate to be processed is exposed is determined by a nitrogen gas, a rare gas having an oxygen concentration of 100 ppm or less,
2. The method for manufacturing a semiconductor device according to claim 1, wherein the method is varied among a reducing gas and a mixed gas thereof. 5. The semiconductor according to claim 1, wherein the flow rate of the gas to be exposed to the substrate to be processed, which is introduced into the reaction vessel, is changed in a range of more than 0 slm and 25 slm or less. Device manufacturing method. 6. A position of the substrate to be processed, wherein a distance from an electron beam generating unit for generating the electron beam is 50 mm or more and 120 m or more.
2. The method according to claim 1, wherein the value is varied within a range of not more than m. 7. An amount of electrons incident on the substrate to be processed per unit time is 4 μC / cm ² · sec or more and 10 μC / cm <sup>2.
2. The</sup> method for manufacturing a semiconductor device according to claim 1, wherein the variation is performed in a range of not more than cm ² · sec. 8. A method according to claim 1, wherein at least one of a pre-heat treatment performed in the reaction vessel before the step of curing the insulating film material and a post-heat treatment performed in the reaction vessel after the step of curing the insulating film material is further performed. And the pressure in the reaction container, the temperature of the substrate to be processed, the gas type to which the substrate to be processed is exposed, and the inside of the reaction container when at least one of the pre-heat treatment and the post-heat treatment is performed. 2. The method according to claim 1, wherein at least one of a flow rate of a gas introduced into the substrate and a position of the substrate to be processed is changed. 9. The method according to claim 8, wherein the pressure in the reaction vessel when at least one of the pre-heat treatment and the post-heat treatment is being performed is changed within a range of more than 0 Torr and not more than 400 Torr. The manufacturing method of the semiconductor device described in the above. 10. The method according to claim 1, wherein the temperature of the substrate to be processed is varied within a range of 200 ° C. or more and 500 ° C. or less when at least one of the pre-treatment step and the post-heat treatment step is performed. 9. The method for manufacturing a semiconductor device according to item 8. 11. The method according to claim 1, wherein at least one of the pre-heat treatment and the post-heat treatment is performed to determine a variation in a gas type to which the substrate is exposed. The method for manufacturing a semiconductor device according to claim 8, wherein the semiconductor device is varied among a gas and a mixed gas thereof. 12. The method according to claim 11, wherein at least one of said pre-heat treatment and said post-heat treatment is performed, wherein a flow rate of a gas introduced into said reaction vessel and exposed to said substrate to be processed is
9. The method of manufacturing a semiconductor device according to claim 8, wherein the variation is made in a range larger than 0 slm and 25 slm or less. 13. When at least one of the pre-heat treatment and the post-heat treatment is performed, the position of the substrate to be processed is adjusted to a distance from an electron beam generator for generating the electron beam of 50 mm or more and 120 mm or less. 9. The method for manufacturing a semiconductor device according to claim 8, wherein the method is varied within a range. 14. The method according to claim 1, wherein the insulating film is an organic silicon oxide film. 15. The method according to claim 1, wherein the insulating film is a polymethylsiloxane film. 16. The method of manufacturing a semiconductor device according to claim 1, further comprising a step of burying a wiring containing Cu as a main component in a surface of said insulating film.