JPH118236A - Method of forming low dielectric constant film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a low dielectric constant film having a low relative dielectric constant by a method, wherein a vapor growth operation is conducted using a raw gas containing a specific component, and the vapor growth dielectric film is heat treated. SOLUTION: A raw gas, formed by mixing silicon atom containing gas, oxygen atom containing gas and diluted gas, is introduced into a chamber, and a protective film is formed on a semiconductor substrate 2. Then, a low dielectric constant film is formed on the semiconductor substrate 2. Silicon atom containing gas, silicon-oxidizing gas and organic molecule containing gas are introduced through different feeding paths, and they are fed into the chamber via a diffusion plate 16. Sin H2n+2 and H2 O2 are introduced and mixed, and a silanol is formed, (Cn H2n+1 O)NH is mixed while proceeding with dehydration-condensation into the silanol, where x+y=3 and x>=1. Then the semiconductor substrate 2 is heat treated. As a result, a low dielectric constant film, having a low relative dielectric constant, is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a low dielectric constant film, and more particularly to a method for forming an extremely low dielectric constant film containing bubbles using a vapor phase growth method. It is.

[0002]

2. Description of the Related Art With demands for miniaturization, low power consumption, high speed, etc. of semiconductor devices, lowering the dielectric constant of an interlayer insulating film is being studied as a means for meeting these requirements. Conventionally, a dielectric material having a reduced relative dielectric constant by containing a carbon atom or a fluorine atom has been used.

As a dielectric material containing carbon atoms, organic S
OG, polyimide, parelin (polyparaxylylene) and the like are known. It is understood that these dielectric materials have a low dielectric constant by containing an alkyl group to lower the density of the material and to have a low polarizability of the molecule itself.

As a dielectric material containing a fluorine atom, Si
OF is known. The dielectric material is Si-OS
By terminating the i-bond with a fluorine atom, the density of the material is reduced, and the polarizability of fluorine itself is low.
It has a low dielectric constant.

[0005] As the requirements for the interlayer insulating film, not only a low dielectric constant but also an excellent gap fill capability and global flattening are important for embedding between wirings. One way to meet these requirements is to use the APL (Advanced Planari
Zation Layer) technology is known and allows for gap fill and some global flattening.

In this APL technique, the source gas is SiH ₄
And H ₂ O ₂ , the semiconductor substrate is cooled to a temperature of about 0 ° C. and CVD (VPE) is performed to form a SiO ₂ insulating film having a liquid-like shape on the surface of the semiconductor substrate. Is done. The gap fill capability of this SiO ₂ insulating film can be up to an aspect ratio of about 4, and the global flattening can fill a 10 μm gap (space) flat. However, when the temperature of the semiconductor substrate is increased to 10 ° C. or more, the fluidity of the raw material on the semiconductor substrate is lost, and the global flattening ability is gradually reduced.

[0007]

However, in this APL technique, good results can be obtained with respect to gap fill capability and global flattening, but sufficient results have not always been obtained with respect to lowering the dielectric constant. The relative dielectric constant of the interlayer insulating film obtained by the APL technique is about 4 to 5, which is equivalent to that of a conventional SOG film or an O ₃ -TEOS film using TEOS (tetraethoxysilane) as a source gas. At rest. Further, since the main component of the interlayer insulating film is silicon oxide (SiO ₂ ) in the first place, even if the relative dielectric constant is reduced in an ideal process, the limit is about 3.8. Further, since a hydroxyl group (—OH) contained in the interlayer insulating film has an effect of increasing the relative dielectric constant, the relative dielectric constant tends to be higher than that of silicon oxide.

Although a technique of lowering the relative dielectric constant to about 3.5 by mixing the raw material gas with fluorine atoms has been studied, the demand for further miniaturization of a semiconductor device or the like has led to a demand for 3.0. There is an increasing need for dielectric materials that achieve the following relative dielectric constants.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. In forming a semiconductor device, the present invention is excellent in gap fill ability and global flattening ability and has a very low relative dielectric constant. An object of the present invention is to provide a method for forming a dielectric film.

[0010]

The method of forming a low dielectric constant film according to the present invention comprises the steps of forming at least Si _n H _{2n + 2} , H ₂ O ₂ and (C _n H
Vapor-phase growth is performed using a source gas containing _{2n +} 1O) _x NH _y (where x + y = 3, x ≧ 1), and the dielectric film that has been vapor-grown is heat-treated.

Further, at least Si _n H _{2n + 2} , H ₂ O ₂ ,
Vapor phase growth is performed using a source gas containing (C ₆ H ₅ O) _x NH _y (where x + y = 3, x ≧ 1), and the vapor-grown dielectric film is heat-treated.

Further, these source gases further include at least polyfluoroethylene, or at least an organic silane gas, or at least a polyfluoroethylene and an organic silane gas.

[0013]

According to the present invention, when a vapor phase growth is performed using the above-mentioned raw material gas containing at least Si _n H _{2n + 2} , H ₂ O ₂ and (C _n H _{2n + 1} O) _x NH _y , Si _n H _{2n + 2} Silanol (Si (OH) _x ) is formed in the course of the reaction between H ₂ O ₂ and H ₂ O _2, and further, during this reaction course, the organic molecule (C _n H _{2n +} ) of (C _n H _{2n + 1} O) _x NH _{y 1}
O) is condensed and mixed as fine particles on the order of nanometers to form a dielectric film in which fine particles remain in the film. When the dielectric film is heat-treated, the organic components of the fine particles are separated, and a low dielectric constant film having fine bubbles is formed.

Further, at least the above-mentioned Si _n H _{2n + 2} , H ₂
When gas phase growth is performed using a source gas containing O ₂ , (C ₆ H ₅ O) _x NH _y , silanol (Si (OH) _{x in the} course of reaction between Si _n H _{2n + 2} and H ₂ O _2. ) is formed, further in this reaction _{process, (C 6 H 5 O)} x NH y organic molecules (C ₆ H ₅ O)
Are condensed and mixed as fine particles on the order of nanometers to form a dielectric film in which fine particles remain in the film. When the dielectric film is heat-treated, the organic components of the fine particles are separated, and a low dielectric constant film having fine bubbles is formed.

If these source gases further include at least polyfluoroethylene, or at least organic silane gas, or at least polyfluoroethylene and organic silane gas, a low dielectric constant film having a lower relative dielectric constant is formed.

[0016]

Embodiment

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is a longitudinal sectional view schematically showing a multilayer wiring structure using the low dielectric constant film of the present invention.
Describes a plasma CVD method for forming this multilayer wiring structure.
FIG. 3 is a longitudinal sectional view schematically showing the structure of the apparatus, and FIG. 3 is a longitudinal sectional view schematically showing the structure of a low pressure CVD apparatus for forming a low dielectric constant film.

The multilayer wiring structure shown in FIG. 1 has metal wirings 4 and 4 'on a surface of a semiconductor substrate 2 on which semiconductor elements are formed.
And the protective films 6 and 6 ′, the low dielectric constant films 8 and 8 ′ of the present invention, and the insulating films 10 and 10 ′ are laminated, and the metal wiring 4 is formed via the via contact BC formed in a part of the insulating film 10.
4 'has a structure in which a part thereof is electrically connected.

Hereinafter, the method of forming the low dielectric constant films 8, 8 'will be described.
A description will be given together with the process of forming this multilayer wiring structure. In the first step, the semiconductor substrate 2 on which the semiconductor elements and the metal wiring 4 for electrically wiring these elements are formed is introduced into a chamber of a capacitively coupled plasma CVD apparatus A shown in FIG. A protective film 6 is formed thereon. When forming the protective film 6, the degree of vacuum in the chamber is set to, for example, 100
Pa, the temperature of the semiconductor substrate 2 is maintained at, for example, 350 ° C., and a frequency of 13.56 MH is applied between the upper electrode 12 and the lower electrode 14.
A high frequency power of z is applied at, for example, 1.0 W / cm ² .
Then, a raw material gas containing a mixture of SiH ₄ or the like as a gas containing silicon atoms, N ₂ O or the like as a gas containing oxygen atoms, and He or the like as a diluting (carrier) gas is introduced into the chamber, thereby mounting on the lower electrode 14. Protective film 6 made of SiO ₂ insulating film on metal wiring 4 of semiconductor substrate 2 placed
To form

Next, in a second step, the semiconductor substrate 2 on which the protective film 6 has been formed is introduced into the chamber of the low-pressure CVD apparatus B shown in FIG. To form When the low dielectric constant film 8 is formed, the degree of vacuum in the chamber is kept at, for example, 200 Pa, the temperature of the diffusion plate 16 is kept at, for example, 100 ° C., and the temperature of the semiconductor substrate 2 placed on the mounting table 18 is kept at about 0 ° C. Furthermore, for example, Si _n H _{2n + 2} as the gas containing silicon atoms at a flow rate of 50 sccm, flow rate of 200sccm for example H ₂ O ₂ to oxidize the silicon
As a gas containing organic molecules, for example, (C _n H _{2n + 1} O) ₂
NH is introduced at a flow rate of 200 sccm through separate supply channels, and these source gases are supplied into the chamber via the diffusion plate 16.

[0020] Then, Si _n H _{2n + 2} and H ₂ O ₂ to form a silanol (Si (OH) _x) by mixing by introducing, advancing the dehydration condensation reaction of the silanol. Furthermore, during the course of the dehydration condensation reaction, (C _n H
_{2n + 1} O ₂ ) NH is mixed with silanol. This allows
Organic molecules of (C _n H _{2n + 1} O) ₂ NH (C _n H _{2n + 1} O) are condensed to form fine particles of the order of nanometers and mixed into the silanol, and upon completion of the dehydration condensation reaction of the silanol, An SiO ₂ dielectric film in which fine particles of organic molecules remain uniformly distributed in the film is deposited flatly on the surface of the protective film 6 of the semiconductor substrate 2.

Next, the semiconductor substrate 2 is heat-treated in a nitrogen atmosphere at atmospheric pressure within a temperature range of 150 to 200.degree. By this heat treatment, the polymerization of the SiO ₂ dielectric film proceeds, and the organic components of the remaining fine particles are separated and vaporized and evaporated out of the SiO ₂ dielectric film, and bubbles of the order of nanometers are formed in the film. Low dielectric constant film 8 as it remains
Is formed.

As a gas containing organic molecules, (C _n H
_{2n +} 1 O) has been described the case of using ₂ NH, may be used _{(C n H 2n + 1 O} ) 3 N and _{(C n H 2n + 1 O} ) NH 2 instead. When (C _n H _{2n + 1} O) ₃ N is used, (C _n H
The content ratio of organic molecules in the SiO ₂ dielectric film is larger than that of _{2n + 1} O) ₂ NH, and the low dielectric constant film 8 having a higher content ratio of bubbles can be formed after the heat treatment. On the other hand, (C _n H
_{When 2n + 1} O) NH ₂ is used, the content of organic molecules in the SiO ₂ dielectric film is smaller than that of (C _n H _{2n + 1} O) ₂ NH, and the low dielectric constant with less content of bubbles after heat treatment. A film 8 can be formed. The low dielectric constant film 8 containing bubbles can also be formed by using an aromatic gas such as (C ₆ H ₅ O).

The low dielectric constant film 8 formed as described above has a very small relative dielectric constant in the range of 1.3 to 2.0, a gap fill capability of up to an aspect ratio of 4, and global flattening. Wiring interval 10
It has a substantially flat shape up to μm, has heat resistance of about 400 ° C. or higher, and exhibits excellent characteristics as an interlayer insulating film.

Next, in the third step, a similar or the CVD method a first step, a sputtering method, or by spin-on method or the like, on the low dielectric constant film 8, about the thickness of SiO ₂ insulating film 0 A 3 .mu.m insulating film 10 is formed. Further, an annealing process is performed after the formation of the insulating film 10 to remove moisture remaining in the low dielectric constant film 8 formed in the second step.
In this process, using a general diffusion furnace, the temperature is about 400
Annealing is performed in a nitrogen atmosphere at about 30 minutes.

Next, a hole for a via contact is formed at a predetermined portion by resist-patterning the insulating film 10 and performing an etching process.

By repeating the same processing as the first to third steps, the metal wiring 4 ′ is formed on the insulating film 10.
And a via contact, a protective film 6 ', a low dielectric constant film 8', and an insulating film 10 'are sequentially formed to realize the multilayer wiring structure shown in FIG.

As described above, as described in this embodiment, a low dielectric constant film having an extremely low relative dielectric constant can be formed by including bubbles in the film. In addition, a low dielectric constant film
Since the protective film and the insulating film are formed using the same CVD method, an interlayer insulating film having a sandwich structure in which a low dielectric constant film is sandwiched between the protective film and the insulating film can be formed continuously. The process steps can be simplified. Further, since the low dielectric constant film containing bubbles has a high adsorptivity to the protective film and the insulating film, an interlayer insulating film having good adhesion can be formed.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIGS. This embodiment relates to another method for forming the low dielectric constant films 8 and 8 '.

A method of forming the low dielectric constant films 8 and 8 'will be described together with the step of forming the multilayer wiring structure shown in FIG. In the first step, a semiconductor substrate 2 on which semiconductor elements and metal wirings 4 for electrically wiring these elements are formed is introduced into a chamber of a capacitively coupled plasma CVD apparatus shown in FIG. Under the same process conditions as the first step in the embodiment, the protective film 6 is formed on the metal wiring 4.

That is, the degree of vacuum in the chamber of the plasma CVD apparatus A is maintained at, for example, 100 Pa, the temperature of the semiconductor substrate 2 is maintained at, for example, 350 ° C., and high-frequency power having a frequency of 13.56 MHz is applied between the upper electrode 12 and the lower electrode 14. 1.
Apply at 0 W / cm ² . Then, a gas containing oxygen atoms such as SiH _{4 is used} as a gas containing silicon atoms, and N ₂ O is used as a gas containing oxygen atoms.
By introducing a source gas mixed with He or the like as a dilution (carrier) gas into the chamber, the lower electrode 1
4 SiO ₂ on the metal wiring 4 of the semiconductor substrate 2 is placed on the
A protective film 6 made of an insulating film is formed.

Next, in a second step, the semiconductor substrate 2 on which the protective film 6 has been formed is introduced into the chamber of the low pressure CVD apparatus B shown in FIG. To form When the low dielectric constant film 8 is formed, the degree of vacuum in the chamber is kept at, for example, 200 Pa, the temperature of the diffusion plate 16 is kept at, for example, 200 ° C., and the temperature of the semiconductor substrate 2 placed on the mounting table 18 is kept at about 0 ° C. Here, the reason why the temperature of the diffusion plate 16 is set to, for example, 200 ° C. is to supply polyfluoroethylene and (C _n H _{2n + 1} O) ₂ NH described later into the chamber without being adsorbed to the diffusion plate 16. It is.

Further, as a gas containing silicon atoms, for example, Si _n H _{2n + 2} at a flow rate of 50 sccm, as an oxidizing gas, for example, H ₂ O ₂ at a flow rate of 200 sccm, and as a gas containing organic molecules, for example, polyfluoroethylene, (C _n H _{2n + 1} O) ₂ NH
At a flow rate of 200 sccm through each separate feed channel. Further, as a fluorocarbon source, for example, CF ₃
This fluorocarbon source is introduced together with a carrier gas (for example, nitrogen gas) using C _n F _2n CF ₃ . The gas flow rate of the carrier gas is, for example, 500 sccm.

Since CF ₃ C _n F _2n CF ₃ is a solid source, it is dissolved in a Florina solvent and then introduced into the chamber by a liquid supply device (not shown). Alternatively, a separate feed means, a CF ₃ C _n F _2n CF ₃ solid was placed in a chamber may be supplied by vaporizing by irradiating high energy light such as a laser. Further, amorphous Teflon having high solubility may be used as the fluorocarbon source.

Then, Si _n H _{2n + 2} and H ₂ O ₂ are introduced and mixed to form silanol (Si (OH) _x ), and the dehydration condensation reaction of this silanol proceeds. Furthermore, during the course of the dehydration condensation reaction, (C _n H
_{2n +} 1 O) a ₂ NH and CF ₃ C _n F _2n CF ₃ mixed silanol. _{Thus, (C n H 2n + 1} O) 2 NH organic molecules _{(C n H 2 n + 1} O) becomes fine particles of nanometer order and condensed mixed into silanol, silanol dehydration condensation reaction Is completed, the SiO ₂ dielectric film in which fine particles of organic molecules remain uniformly distributed in the film is formed on the semiconductor substrate 2.
Is deposited flat on the surface of the protective film 6.

Next, the semiconductor substrate 2 is subjected to a heat treatment in a nitrogen atmosphere at atmospheric pressure within a temperature range of 150 to 200.degree. By this heat treatment, the polymerization of the SiO ₂ dielectric film proceeds, and the organic components of the remaining fine particles are separated and vaporized and evaporated out of the SiO ₂ dielectric film, and bubbles of the order of nanometers are formed in the film. Low dielectric constant film 8 as it remains
Is formed.

The low dielectric constant film 8 thus formed is
The relative permittivity is a value within the range of 2.0 to 2.5. Regarding the gap fill capability, a flat shape was maintained up to an aspect ratio of 4 and the global flatness up to a wiring interval of 10 μm.

Next, in the third step, a similar or the CVD method a first step, a sputtering method, or by spin-on method or the like, on the low dielectric constant film 8, about the thickness of SiO ₂ insulating film 0 A 3 .mu.m insulating film 10 is formed. Further, an annealing process is performed after the formation of the insulating film 10 to remove moisture remaining in the low dielectric constant film 8 formed in the second step.
In this process, using a general diffusion furnace, the temperature is about 400
Annealing is performed in a nitrogen atmosphere at about 30 minutes.

Next, resist patterning is performed on the insulating film 10 and an etching process is performed to form a hole for a via contact at a predetermined portion.

By repeating the same processing as the first to third steps, the metal wiring 4 ′ is formed on the insulating film 10.
And a via contact, a protective film 6 ', a low dielectric constant film 8', and an insulating film 10 'are sequentially formed to realize the multilayer wiring structure shown in FIG.

As described above, the low dielectric constant film according to the present embodiment also has a relative dielectric constant of 3.0 or less, and is excellent in gap fill ability, global flattening ability, and heat resistance. On the other hand, an excellent interlayer insulating film can be realized.

(Third Embodiment) A third embodiment of the present invention will be described with reference to FIGS. This embodiment relates to still another method for forming the low dielectric constant films 8 and 8 '.

A method of forming the low dielectric constant films 8 and 8 'will be described together with the step of forming the multilayer wiring structure shown in FIG. In the first step, the semiconductor substrate 2 on which the semiconductor elements and the metal wirings 4 for electrically wiring these elements are formed is introduced into the chamber of the capacitively-coupled plasma CVD apparatus A shown in FIG. Under the same process conditions as the first step in the embodiment, protective film 6 is formed on metal wiring 4.

That is, the degree of vacuum in the chamber of the plasma CVD apparatus is maintained at, for example, 100 Pa, the temperature of the semiconductor substrate 2 is maintained at, for example, 350 ° C., and high-frequency power having a frequency of 13.56 MHz is applied between the upper electrode 12 and the lower electrode 14, for example. .0
Apply at W / cm ² . Then, a gas containing oxygen atoms such as SiH _{4 is used} as a gas containing silicon atoms, and N ₂ O is used as a gas containing oxygen atoms.
By introducing a source gas mixed with He or the like as a dilution (carrier) gas into the chamber, the lower electrode 1
4 SiO ₂ on the metal wiring 4 of the semiconductor substrate 2 is placed on the
A protective film 6 made of an insulating film is formed.

Next, in the second step, the semiconductor substrate 2 on which the protective film 6 has been formed is introduced into the chamber of the low-pressure CVD apparatus B shown in FIG. To form When the low dielectric constant film 8 is formed, the degree of vacuum in the chamber is kept at, for example, 200 Pa, the temperature of the diffusion plate 16 is kept at, for example, 100 ° C., and the temperature of the semiconductor substrate 2 placed on the mounting table 18 is kept at about 0 ° C.

Further, dimethylsilane (CH ₃ ) ₂ SiH ₂ or monomethylsilane (C
H ₃ ) SiH ₃ , for example, H ₂ O ₂ for oxidizing hydrogen, and (C _n H _{2n + 1} O) ₂ NH as a gas containing organic molecules,
As a fluorocarbon source, for example, CF ₃ C _n F _2n CF
₃ was used, nitrogen, argon, hydrogen or helium is used as the carrier gas of _{CF 3 C n F 2n CF 3} . Regarding the supply flow rates of these source gases, (CH ₃ ) ₂ SiH ₂ or (CH ₃ ) SiH ₃ was 50 sccm, H ₂ O ₂ was 200 sccm,
(C _n H _{2n + 1} O) ₂ NH (gas) is introduced at 200 sccm, and a fluorocarbon carrier gas is introduced at 500 sccm.

Then, (CH ₃ ) ₂ SiH ₂ or (CH ₃ )
By introducing and mixing SiH ₃ and H ₂ O ₂ , silanol (Si (OH) _x ) is formed, and the dehydration condensation reaction of this silanol proceeds. Furthermore, during the course of the dehydration condensation _{reaction, (C n H 2n + 1} O) 2 NH , and CF ₃ C _n F _2n CF
₃ is mixed with silanol. Thereby, (C _n H
_{2n + 1} O) ₂ NH organic molecules (C _n H _{2n + 1} O) condense into nanometer-order fine particles and mix into the silanol. When the silanol dehydration-condensation reaction is completed, the organic molecule fine particles SiO ₂ of but still remaining in uniform distribution in the film
A dielectric film is deposited flat on the surface of the protective film 6 of the semiconductor substrate 2.

Next, the semiconductor substrate 2 is subjected to a heat treatment in a nitrogen atmosphere at atmospheric pressure within a temperature range of 150 to 200 ° C. By this heat treatment, the polymerization of the SiO ₂ dielectric film proceeds, and the organic components of the remaining fine particles are separated and vaporized and evaporated out of the SiO ₂ dielectric film, and bubbles of the order of nanometers are formed in the film. Low dielectric constant film 8 as it remains
Is formed.

The low dielectric constant film 8 thus formed is
The relative permittivity is a value within the range of 1.2 to 2.0. Regarding the gap fill capability, a flat shape was maintained up to an aspect ratio of 4 and the global flatness up to a wiring interval of 10 μm. As a gas containing silicon atoms (C
Since a gas containing a methyl group such as H ₃ ) ₂ SiH ₂ or (CH ₃ ) SiH ₃ is used, a low dielectric constant film is easily obtained. However,
Since the heat resistance tends to be low, it is desirable to use it appropriately according to the application.

Next, in the third step, the same method as in the first step, such as the CVD method, the sputtering method, or the spin-on method, is used to form the SiO ₂ insulating film having a thickness of about 0 on the low dielectric constant film 8. A 3 .mu.m insulating film 10 is formed. Further, an annealing process is performed after the formation of the insulating film 10 to remove moisture remaining in the low dielectric constant film 8 formed in the second step.
In this process, using a general diffusion furnace, the temperature is about 400
Anneal for about 15 minutes in a nitrogen atmosphere at ℃.

Next, resist patterning is performed on the insulating film 10 and an etching process is performed to form a hole for a via contact in a predetermined portion, and the same processes as the first to third processes are repeated. Then, a metal wiring 4 ', a via contact, a protective film 6', a low dielectric constant film 8 ', and an insulating film 10' are sequentially formed on the insulating film 10 to realize the multilayer wiring structure shown in FIG.

As described above, the low dielectric constant film according to the present embodiment also has a relative dielectric constant of 3.0 or less, and is excellent in gap fill capability and global flatness capability. An excellent interlayer insulating film can be realized.

In the first to third embodiments, the protective films 4 and 4 'and the insulating films 10 and 10' are formed of silicon oxide films. However, they may be formed of silicon nitride films. It is possible to realize an interlayer insulating film having excellent capability and global flattening capability and a low dielectric constant.

[0053]

As described above, according to the method of forming a low dielectric constant film of the present invention, since a low dielectric constant film having bubbles is formed by using a CVD method, it is formed by a conventional CVD method. As compared with an interlayer insulating film, an interlayer insulating film having excellent gap fill ability and global flattening ability and having a very low relative dielectric constant can be realized. As a result, the yield does not decrease due to the defective filling capability of the interlayer insulating film, and the parasitic capacitance between the wirings can be further reduced. Consequently, a semiconductor device with high yield and reliability, high operation speed, and low power consumption can be formed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing a multilayer wiring structure using a low dielectric constant film of the present invention.

FIG. 2 is a longitudinal sectional view schematically showing a structure of a plasma CVD apparatus for forming the multilayer wiring structure of FIG.

FIG. 3 shows a reduced pressure CV for forming a low dielectric constant film of the present invention.
It is a longitudinal cross-sectional view which shows the structure of D apparatus typically.

[Explanation of symbols]

2, a semiconductor substrate, 4, 4 'metal wiring, 6, 6' protective film, 8, 8 'low dielectric constant film, 10, 10' insulating film,
A: Plasma CVD device, B: Low pressure CVD device.

Claims (4)

[Claims] 1. At least Si _n H _{2n + 2} , H ₂ O ₂ and (C _n H _{2n + 1} O) _x NH _y (where x + y = 3, x ≧ 1)
A method for forming a low dielectric constant film, comprising performing vapor phase growth using a raw material gas containing, and heat treating a dielectric film grown by vapor phase growth. 2. The method according to claim 2, wherein at least Si _n H _{2n + 2} , H ₂ O ₂ , (C ₆
H ₅ O) _x NH _y (where, x + y = 3, and subjected to gas-phase growth using x ≧ 1) raw material gas containing a low dielectric constant film, which comprises heat-treating the dielectric film grown vapor Formation method. 3. The method for forming a low dielectric constant film according to claim 1, wherein the source gas further contains at least polyfluoroethylene. 4. The method according to claim 1, wherein the source gas further contains at least an organic silane gas.