JP2000106364A - Manufacturing method of insulating film - Google Patents

Abstract

(57) [Summary] [PROBLEMS] An organic insulating film satisfying the relative dielectric constant required for the next-generation device process has a poor film quality, and therefore, it has been studied to use it together with a silicon-based insulating film. The adhesion to the film was very poor and peeling occurred. When a silicon-based insulating film made of a silicon oxide film, a silicon oxynitride film, or a silicon nitride film is formed on a surface of an organic insulating film, an interface between the silicon-based insulating film and the organic insulating film is determined. This is a method of manufacturing an insulating film formed to have a Si-H bond. When an organic insulating film is formed of a fluororesin film, a physical impact is applied to the surface of the fluororesin film before forming the silicon-based insulating film. The treatment may be performed to reduce the bonding with carbon on the surface of the fluororesin film, or a silane coupling agent may be applied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an insulating film, and more particularly to a method of manufacturing a device having a design rule of 0.25 .mu.m or less. The present invention relates to a method for manufacturing an insulating film for forming a film.

[0002]

2. Description of the Related Art Along with demands for miniaturization, low power consumption, and high speed of a semiconductor device, lowering the dielectric constant of an interlayer insulating film has been studied as one of means for realizing the demand. The low-dielectric-constant films disclosed at present lower the relative dielectric constant by containing carbon atoms and fluorine atoms. At present, those having a relative dielectric constant of about 1.5 to 2.5 have been developed.

[0003] As a low dielectric constant film material containing carbon atoms,
Organic SOG (Spin on glass), fluorocarbon polymer, polyimide, polyparaxylylene and the like are well known. It is said that these materials have a low dielectric constant due to a reduction in the density of the material due to the inclusion of a carbon atom, a so-called alkyl group, and a low polarizability of the molecule itself. Further, these materials not only have a low relative dielectric constant but also have heat resistance indispensable as a material of a semiconductor device. Organic SOG has a siloxane structure,
Polyimide has an imide bond, and an organic material such as polyparaxylylene and a fluorocarbon polymer have a benzene ring, thereby securing a certain degree of heat resistance.

On the other hand, as a material of a low dielectric constant interlayer insulating film containing a fluorine atom, a silicon-based oxide containing fluorine (S
iOF) is well known. This material is silicon-
Terminating the oxygen-silicon (Si-O-Si) bond with a fluorine atom lowers the material density, and lowers the relative permittivity due to the low polarizability of the fluorine atom itself. As a matter of course, this SiOF is also excellent in heat resistance.

[0005]

SUMMARY OF THE INVENTION However, SiO
The relative permittivity of the F film is about 3.5, and it is difficult to satisfy the relative permittivity required in the next-generation device process. Further, a fluorocarbon (organic) film having a relative dielectric constant of about 2.0 has poor film quality such as oxidation resistance, heat resistance, pressure resistance, and stress resistance, and is difficult to be applied to a semiconductor device as it is. It has been studied to use it together with a conventionally used silicon oxide film or SiOF film. However, the silicon oxide film and the SiOF film have very poor adhesion to the fluorocarbon (organic) film, and easily peel off. This is because the fluorocarbon (organic) film has a high electronegativity of fluorine and a strong bonding force with carbon, so that no reaction occurs even when other molecules approach. Therefore, in practice, fluororesins characterized by poor adhesion are used as release materials. On the other hand, fluororesin has been attracting attention as a low-dielectric-constant film because there are also materials having a relative dielectric constant of 2 or less.

In order to be introduced into a semiconductor process, good adhesion to a silicon oxide film, a silicon oxynitride film, and a silicon nitride film, which are representative of insulating films, is required. However, when an oxide film or the like is formed on a fluororesin, the adhesion is poor, and peeling may occur. The IEDM (Internatinal Electron Devices Meetin) held in 1997
g) has been reported.

[0007]

SUMMARY OF THE INVENTION The present invention is a method for manufacturing an insulating film which has been made to solve the above problems.

That is, in the first manufacturing method, when a silicon-based insulating film made of a silicon oxide film, a silicon oxynitride film or a silicon nitride film is formed on the surface of the organic insulating film, Si-H at the interface with
This is a manufacturing method for forming a bonding state.

In the first manufacturing method, since the silicon-based insulating film is formed to have a Si—H bond at the interface with the organic insulating film, the interface between the silicon-based insulating film and the organic insulating film is active. It is in a state where it has a dangling bond easily. Therefore, the atoms of the organic insulating film easily enter the active dangling bonds, so that the silicon-based insulating film is formed with good adhesion to the organic insulating film.

In a second manufacturing method, a process of giving a physical impact to the surface of the fluororesin film to reduce bonding with carbon from the surface of the fluororesin film, and a process of giving a physical impact are performed. Silicon oxide film on the surface of the fluororesin film,
Forming a silicon-based insulating film made of a silicon oxynitride film or a silicon nitride film.

[0011] In the second manufacturing method, by performing a treatment for giving a physical impact to the surface of the fluororesin film, a bond with carbon, for example, a bond between carbon and fluorine is broken, and carbon is converted from the fluororesin film to carbon. , The reactivity of the surface of the fluororesin film is increased. Thereafter, since a silicon-based insulating film is formed on the surface of the fluororesin film, the adhesion is improved by bonding silicon atoms or oxygen atoms to carbon atoms of the fluororesin film.

In a third manufacturing method, a step of applying a silane coupling agent to the surface of the fluororesin film, a step of performing a heat treatment for promoting a crosslinking reaction of the fluororesin film, and an application of the silane coupling agent are performed. Forming a silicon-based insulating film made of a silicon oxide film, a silicon oxynitride film, or a silicon nitride film on the surface of the fluororesin film.

In the third manufacturing method, a silane coupling agent is applied to the surface of the fluororesin film. Since the silane coupling agent has a molecular structure having a high affinity with the fluororesin film and a molecular structure having a high affinity with the silicon-based insulating film, the silane coupling agent is used to bond the fluorine resin film to the silicon via the silane coupling agent. Adhesion with the system insulating film is improved. Then, by performing a heat treatment for promoting a crosslinking reaction of the fluororesin film, the fluororesin film is polymerized.

In a fourth manufacturing method, a step of applying a fluororesin on a substrate to form a fluororesin film, a step of drying the fluororesin film, and applying a silane coupling agent to the surface of the fluororesin film A silicon oxide film, a silicon oxynitride film or a silicon nitride film on the surface of the fluororesin film on which a silane coupling agent has been applied, and a heat treatment for accelerating a crosslinking reaction of the fluororesin film. Forming a step.

In the fourth manufacturing method, since the fluororesin film is formed by coating and then dried, the solvent in the fluororesin film formed by coating evaporates. Thereafter, a silane coupling agent is applied to the surface of the fluororesin film. Since the silane coupling agent has a molecular structure having a high affinity with the fluororesin film and a molecular structure having a high affinity with the silicon-based insulating film, the silane coupling agent is used to bond the fluorine resin film to the silicon via the silane coupling agent. Adhesion with the system insulating film is improved. Moreover, since the silane coupling agent is applied in a state where the solvent in the fluororesin film is evaporated, that is, in a state where the fluororesin network is incomplete, a heat treatment for promoting crosslinking is performed. Since the crosslinking with the silane coupling agent also proceeds at the same time as the crosslinking proceeds, the adhesion is further improved. Then, as the crosslinking proceeds, the fluororesin film is polymerized.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to a first manufacturing method of the present invention will be described with reference to FIG.

As shown in FIG. 1A, a silicon oxide film 12 is formed on a substrate 11 by a general CVD method using monosilane (SiH ₄ ) and oxygen (O ₂ ) as source gases.
Is formed to a thickness of, for example, about 500 nm. This silicon oxide film 12 is formed by using tetraethoxysilane (T
It can also be formed by a plasma CVD method using EOS) and oxygen.

Next, for example, an aluminum-silicon alloy film is formed as a wiring material film on the silicon oxide film 12 by a sputtering apparatus. Next, after a resist film is formed by a general resist coating technique, an etching mask is formed by the resist film by lithography technique, and the wiring material film is etched by the etching technique using the resist film to form the wiring 13. After that, the etching mask is removed.

Next, a silicon oxide film 14 for covering the wiring 13 is formed on the silicon oxide film 12 by, for example, 100
It is formed to a thickness of nm. This film thickness is a film thickness on the substrate 11 in a region where the wiring 13 is not formed.
Usually, the thickness is smaller than the above-mentioned thickness between the three. The silicon oxide film 14 is formed by, for example, CVD (for example, plasma CVD) using monosilane and dinitrogen monoxide.

Next, the organic insulating film 15 is made of, for example, a kind of fluororesin, poly-para-xylylene fluoride, for example, 500 nm.
m. A general reduced pressure CV is used for the film forming apparatus.
D apparatus was used, and diparaxylylene fluoride was used as a raw material. At the time of CVD, the above-mentioned raw material is heated to 200 ° C. to be sublimated, and decomposed at 650 ° C. to a xylylene monomer.
It was introduced on a substrate heated to 50 ° C. As a result, polyxylylene fluoride was deposited to a thickness of about 500 nm. The organic insulating film 15 may be formed of a material other than the above materials. As an example, it is also possible to use a fluorine resin such as a polytetrafluoroethylene resin or a plasma fluorocarbon resin, or a low dielectric constant organic insulating film other than the fluorine resin. When forming the organic insulating film 15, it is desirable to apply a silane coupling agent as an adhesion layer on the base.

Next, as shown in FIG. 1B, a silicon-based insulating film 16 is formed on the organic insulating film 15 by, for example, 500
It is formed to a thickness of nm.

In the film formation in the first step, a film having a large number of bonds between silicon and hydrogen (hereinafter, referred to as Si—H bond) is formed by plasma CVD using monosilane (SiH ₄ ) as a main component. A lower layer of the insulating film 16 is formed. Since this film has many active dangling bonds, the adhesion to the base is improved. An example of the film forming conditions is a monosilane (SiH ₄ ) gas (flow rate: 100 s).
ccm) and nitrous oxide (N ₂ O) gas (flow rate: 100
sccm) and ammonia (NH ₃ ) gas (flow rate: 0 to 1)
00 sccm) and nitrogen (N ₂ ) gas (flow rate: 1000 s)
ccm), the pressure of the film formation atmosphere is 102 Pa, the set temperature of the substrate 11 is 350 ° C., and the plasma power is 500
W was set. Note that the above sccm represents a volume flow rate (cm ³ / min) in a standard state.
It is expressed using m.

Subsequently, the film formation in the second step is performed by plasma enhancement CVD in a reducing atmosphere using monosilane (SiH ₄ ) gas, dinitrogen monoxide (N ₂ O) gas, and ammonia (NH ₃ ) gas. Then, an upper layer portion of the silicon-based insulating film 16 is formed on a lower layer portion of the silicon-based insulating film 16 formed in the first step. As an example of the film forming conditions, a monosilane (SiH ₄ ) gas (flow rate: 10
0 sccm) and nitrous oxide (N ₂ O) gas (flow rate: 1)
500 sccm) and ammonia (NH ₃ ) gas (flow rate:
0-100 sccm) and nitrogen (N ₂ ) gas (flow rate: 10
00 sccm) and the pressure of the film formation atmosphere is 102 P
a, The set temperature of the substrate 11 was set to 350 ° C., and the plasma power was set to 500 W.

In the formation of the silicon-based insulating film 16, a silicon oxide film or a silicon oxynitride film is obtained by adjusting the flow rate of ammonia gas. For example, if the flow rate of the ammonia gas is set to 0, the silicon-based insulating film 16 is formed on the silicon oxide film, and if the ammonia gas is used, the silicon-based insulating film 16 is formed on the silicon oxynitride film.

Although a monosilane (SiH ₄ ) gas is used in the above film formation, a higher silane gas such as disilane (Si ₂ H ₆ ) may be used. Although nitrous oxide (N ₂ O) gas was used as an oxygen source, H ₂ O (gas) was used.
It is also possible to use a reducing gas having a nitrogen atom such as hydrazine as a nitrogen source.

Further, dinitrogen monoxide (N
₂ O) except the gas monosilane (SiH ₄₎ gas and ammonia (NH ₃₎ gas and nitrogen (N ₂₎ with a gas,
The silicon-based insulating film 16 can be formed as a silicon nitride film. However, since the relative permittivity of the silicon nitride film is higher than that of the silicon oxide film and the silicon oxynitride film, the capacitance between wirings increases. Therefore, from the viewpoint of the capacitance between wirings, it is preferable that the wiring be formed of a silicon oxide film or a silicon oxynitride film.

In the first manufacturing method, since the silicon-based insulating film 16 is formed so as to have a Si—H bond at the interface with the organic insulating film 15, the silicon-based insulating film 16 is formed with the organic insulating film 15. The interface is in a state having an active dangling bond. Therefore, the atoms of the organic insulating film 15 are bonded to the active dangling bonds, so that the silicon-based insulating film 16 is formed with good adhesion to the organic insulating film 15.

Next, a second embodiment according to the first manufacturing method of the present invention will be described with reference to FIG. 2, using a process for forming a damascene wiring structure as an example. 2, the same components as those described with reference to FIG. 1 are denoted by the same reference numerals.

As shown in FIG. 2A, a silicon oxide film 12 is formed on a substrate 11 and the silicon oxide film 12 is formed.
An organic insulating film 15 is formed thereon. When the organic insulating film 15 is formed, it is desirable to apply a silane coupling agent as an adhesion layer on a base. Next, a silicon-based insulating film 16 is formed on the organic insulating film 15 as an etching mask of the organic insulating film 15 by using, for example, monosilane (S
i—H ₄ ) by plasma CVD using Si—H
It is formed of a film with many bonds. Therefore, since this film has many active dangling bonds, the adhesion to the base is improved. The above components are formed in the same manner as described with reference to FIGS.

Thereafter, as shown in FIG. 2B, after forming a resist film (not shown) by applying a resist, the resist film is patterned by lithography to form an etching mask (not shown). The upper portion of the groove 18 is formed in the silicon-based insulating film 16 by etching using the etching mask. Further, the organic insulating film 15 is etched using the silicon-based insulating film 16 as an etching mask to form a groove 18. In the etching of the organic insulating film 15, the etching mask is simultaneously etched and removed.

Next, a barrier layer 19 is formed on the inner wall of the groove 18 by, for example, a tantalum nitride film by CVD or sputtering, and then a copper film serving as a seed for copper plating is formed. After the trench 18 is filled with copper by electrolytic copper plating, the excess copper and the tantalum nitride film on the silicon-based insulating film 16 are removed by, for example, CMP to form a wiring 20 made of copper inside the trench 18.

In the method of manufacturing a damascene wiring structure described with reference to FIG. 2, since the silicon-based insulating film 16 is formed so as to have a Si—H bond at the interface with the organic insulating film 15, the silicon-based insulating film 16 is formed. The interface with the organic insulating film 15 has an active dangling bond. Therefore, the atoms of the organic insulating film 15 are bonded to the active dangling bonds, so that the silicon-based insulating film 16 is formed with good adhesion to the organic insulating film 15.

A first embodiment according to the second manufacturing method of the present invention will be described with reference to FIG. 3, the same components as those described with reference to FIG. 1 are denoted by the same reference numerals.

As shown in FIG. 3A, a silicon oxide film 12 is formed on the substrate 11 to a thickness of, for example, about 500 nm. Next, after forming the wiring 13 on the silicon oxide film 12, a silicon oxide film 14 covering the wiring 13 is formed on the silicon oxide film 12 to a thickness of, for example, 100 nm. The formation of each component is performed in the same manner as described with reference to FIG.

Next, the substrate is irradiated with plasma using dinitrogen monoxide (N ₂ O) gas. In this plasma irradiation,
As an example, a parallel plate type plasma processing apparatus was used as a plasma generator, and RF (13.56 MHz) power was set to, for example, 300 W.

Next, a silane coupling agent is applied to the surface of the silicon oxide film 14 by, for example, a spin coating method. This silane coupling agent has the following chemical formula, for example, CF ₃ (CF ₂ ) _n CH ₂ SiC
l ₂ (where n represents an integer of 2 or more), CF ₃ (CF
₂ ) _n CH ₂ Si (OMe) ₃ (where n represents an integer of 2 or more and Me represents a methyl group) or CF ₃ (C
F ₂ ) _n H ₂ Si (OH) ₃ (where n represents an integer of 2 or more) is used. The silane coupling agent described above is an example, and other silane coupling agents can be used.

Next, a fluororesin film 25 is formed on the silicon oxide film 14 with, for example, a polytetrafluoroethylene resin (for example, Teflon AF (trade name) manufactured by DuPont) to a thickness of, for example, 500 nm. Form. The polytetrafluoroethylene resin is not limited to the Teflon AF as long as it has a chemical structure represented by the formula (1).

[0038]

Embedded image

In this film formation, the fluororesin raw material was dissolved in a fluorocarbon-based solvent, and the viscosity was adjusted to 30 cp. It is applied on the silicon oxide film 14 by a spin coating method to form a thin film having a thickness of 500 nm. The rotation speed at this time was, for example, 3000 rpm. Next, baking was performed for 2 minutes in an inert gas atmosphere, for example, a nitrogen gas atmosphere at 100 ° C. and atmospheric pressure.

Alternatively, a fluororesin may be formed by plasma CVD. The film forming conditions are, for example, to improve heat resistance by using, for example, an octafluorobutene (C ₄ F ₈ ) gas or a tetrafluoroethylene (C ₂ F ₄ ) gas as a fluorocarbon-based gas as a process gas. Acetylene (C ₂ H ₂ ) or ethylene (C ₂ H
₄ ) Mix. General CVD conditions include plasma power of 500 W, C ₄ F ₈ of 100 sccm, C ₂
H ₂ at 200 sccm, pressure of film formation atmosphere at 26.7P
A predetermined pressure in a range of a to 667 Pa and a substrate temperature are set to a predetermined temperature in a range of 150 ° C. to 350 ° C.

Next, a treatment for giving a physical impact to the surface of the fluororesin film 25 is performed to reduce the bonds between the fluororesin film 25 and carbon, for example, the bonds between carbon and fluorine and the bonds between carbon atoms. The treatment for giving the physical impact is performed by plasma irradiation, sputtering, ion irradiation, or the like. Here, as an example, the irradiation is performed by plasma irradiation.

The plasma irradiation is performed as follows, for example. The gas in the plasma generation atmosphere includes hydrogen (H ₂ ) gas (flow rate: 100 sccm) and argon (A).
r) Gas (flow rate: 50 sccm), the pressure of the atmosphere is set to 2.67 Pa, and plasma irradiation is performed by generating high-density plasma with a plasma power in the range of 500 W to 2 kW.

These conditions are set to optimal values depending on the type of fluororesin. These values are obtained by, for example, using X-ray photoelectron spectroscopy (X-ray photoelectron
n spectroscopy: measured by an XPS apparatus, it was confirmed that the bond between carbon and fluorine (hereinafter referred to as CF bond) and the bond between carbon atoms (hereinafter referred to as CC bond) were cut in only a few atomic layers. It is desirable to check and set. In the case of the present embodiment, it was confirmed that the CF bond was broken within the above condition range.

The plasma source gas is not limited to the gas described above, but may be a nitrogen (N ₂ ) gas,
An inert gas such as a helium (He) gas or a neon (Ne) gas can also be used.

Next, as an inert atmosphere, for example, 35
Heat treatment (curing) was performed in a nitrogen (N ₂ ) gas atmosphere at 0 ° C. Here, the heat treatment is performed in a nitrogen atmosphere, but may be performed in a rare gas atmosphere.

Next, as shown in FIG. 3B, a silicon-based insulating film 16 is formed of, for example, a silicon oxide film to a thickness of, for example, 500 nm on the fluororesin film 25 subjected to the plasma irradiation. The film formation is performed, for example, by using monosilane (SiH ₄ ) gas and dinitrogen monoxide (N ₂ O) as the source gas.
This was performed by plasma enhancement CVD (hereinafter, referred to as PECVD) in a reducing atmosphere using a gas. The film forming conditions are, for example, monosilane (SiH
₄ ) The flow rate of gas is 100 sccm, the flow rate of nitrous oxide gas is 500 sccm, and nitrogen is used as a carrier gas.
The flow rate was 1000 sccm. Further, the pressure of the film formation atmosphere is set to 102 Pa, and the set temperature of the silicon substrate 11 is set to 3
The temperature was set to a predetermined temperature in the range of 00 ° C. to 350 ° C., and the plasma power was set to 500 W.

When the silicon-based insulating film 16 is formed under the above conditions, a large amount of Si—H bonds are included, so that the hygroscopicity is reduced. In this case, since a large amount of hydrogen (H) is contained, heat treatment is preferably performed in an inert gas atmosphere at about 400 ° C. after the film formation.

Although a monosilane (SiH ₄ ) gas was used in forming the silicon-based insulating film 16, disilane (Si
It is also possible to use a higher silane gas such as ₂ H ₆ ). Although nitrous oxide (N ₂ O) gas was used as the oxygen source, H ₂ O (gas) or the like may be used.

In the second manufacturing method, the fluorine resin film 2
By performing a process of giving a physical impact to the surface of 5,
Since the bonds with carbon in several atomic layers on the surface of the fluororesin film 25 are broken and reduced, the reactivity of the surface of the fluororesin film 25 is enhanced. After that, since the silicon-based insulating film 16 is formed on the surface of the fluororesin film 25, the silicon-based insulating film is formed on the surface of the fluororesin film 25 by bonding silicon atoms or oxygen atoms with carbon atoms of the fluororesin film. The adhesion of No. 16 is improved. In the process of giving the physical impact, only the bond with carbon of several atomic layers on the surface of the fluororesin film 25 is broken, so that the heat resistance and the relative dielectric constant of the fluororesin film 25 due to the destruction of the CF bond are reduced. Has almost no effect.

As the silicon-based insulating film 16, it is also possible to use the silicon-based insulating film 16 according to the manufacturing method described in the first embodiment of the present invention. That is, in the formation of the silicon-based insulating film 16, the lower layer of the silicon-based insulating film 16 is formed by plasma CVD using monosilane (SiH ₄ ) as a main component and having many Si—H bonds in the first step. Form. This film has many active dangling bonds and has good adhesion to the base. As an example of the film forming conditions, monosilane (SiH ₄ ) gas (flow rate: 100 sccm), dinitrogen monoxide (N ₂ O) gas (flow rate: 100 sccm), and ammonia (NH ₃ ) gas (flow rate: 0 to 100 sccm) And nitrogen (N ₂ ) gas (flow rate: 1000 sccm), the pressure of the film formation atmosphere is 102 Pa, and the set temperature of the silicon substrate 11 is 350
° C and plasma power were set to 500W.

Subsequently, the film formation in the second step is performed by PECV in a reducing atmosphere using monosilane (SiH ₄ ) gas, dinitrogen monoxide (N ₂ O) gas, and ammonia (NH ₃ ) gas.
D is performed to form the silicon-based insulating film 16 in a portion above the lower portion of the silicon-based insulating film 16 formed in the first step. As an example of the film forming conditions, monosilane (SiH ₄ ) gas (flow rate: 100 sccm), dinitrogen monoxide (N ₂ O) gas (flow rate: 1500 sccm), and ammonia (NH ₃ ) gas (flow rate: 0 to 100 sccc)
m) and nitrogen (N ₂ ) gas (flow rate: 1000 sccm), the pressure of the film formation atmosphere is 102 Pa, the set temperature of the silicon substrate 11 is 350 ° C., and the plasma power is 500 W.
Set to.

In the formation of the silicon-based insulating film 16, a silicon oxide film or a silicon oxynitride film is obtained by adjusting the flow rate of ammonia gas. For example, if the flow rate of ammonia gas is set to 0, the silicon-based insulating film 16 is formed of a silicon oxide film, and if an ammonia gas is used, the silicon-based insulating film 16 is formed of a silicon oxynitride film.

Although a monosilane (SiH ₄ ) gas is used in the above film formation, a higher silane gas such as disilane (Si ₂ H ₆ ) can be used. Although nitrous oxide (N ₂ O) gas was used as an oxygen source, H ₂ O (gas) was used.
It is also possible to use a reducing gas having a nitrogen atom such as hydrazine as a nitrogen source.

As described above, by forming the silicon-based insulating film 16 with the Si-H bond at the interface with the fluororesin film 25, the interface of the silicon-based insulating film 16 with the fluororesin film 25 is activated. It has a dangling bond. Therefore, the atoms of the fluororesin film 25 enter the active dangling bonds, so that the silicon-based insulating film 16 is formed with good adhesion to the fluororesin film 25.

Next, a second embodiment according to the second manufacturing method of the present invention will be described with reference to FIG. 4, using a process for forming a damascene wiring structure as an example. 4, the same components as those described with reference to FIG. 3 are denoted by the same reference numerals.

As shown in FIG. 4A, after a silicon oxide film 12 is formed on a substrate 11, dinitrogen monoxide (N ₂
O) The plasma using gas is applied to the substrate (silicon oxide film 1).
Irradiate in 2). Further, it is desirable to apply a silane coupling agent to the surface of the silicon oxide film 12 by, for example, a spin coating method. After that, a fluororesin film 25 is formed on the silicon oxide film 12. Each component is formed in the same manner as described with reference to FIG.

Next, plasma irradiation is performed as a process for giving a physical impact to the surface of the fluororesin film 25 to reduce the bonding of the fluororesin film 25 to carbon. As a treatment method for applying the physical impact, for example, a method such as ion irradiation or sputtering can be used in addition to plasma irradiation.

Next, as described with reference to FIG. 3, a heat treatment (curing) was performed in an inert atmosphere (for example, a nitrogen (N ₂ ) gas atmosphere at 350 ° C.).

Next, as shown in FIG. 4B, a silicon-based insulating film 16 serving as an etching mask for the fluororesin film 25 is formed on the fluororesin film 25 by a silicon oxide film, a silicon oxynitride film or a nitride film. It is formed of a silicon film. The method of forming the film is the same as the method of forming the silicon-based insulating film 16 in the first embodiment described with reference to FIG.

Thereafter, as shown in FIG. 4C, an upper portion of the groove 18 is formed in the silicon-based insulating film 16 in the same manner as in the second embodiment described with reference to FIG. Further, using the silicon-based insulating film 16 as an etching mask, the fluorine resin film 25 is etched to form the groove 18. Next, the barrier metal layer 1 is formed on the inner wall of the groove 18.
9 is formed of, for example, a tantalum nitride film, and then a copper film serving as a seed for copper plating is formed. After the trench 18 is filled with copper by electrolytic copper plating, the excess copper and the tantalum nitride film on the silicon-based insulating film 16 are removed by, for example, CMP to form a wiring 20 made of copper inside the trench 18.

In the method of manufacturing a damascene wiring structure described with reference to FIG. 4, the surface of the fluororesin film 25 is subjected to a physical impact to thereby perform C-F bonding and C-C Since the bond is broken and reduced, the reactivity of the surface of the fluororesin film 25 is increased. Thereafter, the silicon-based insulating film 16 is formed on the surface of the fluororesin film 25.
Since silicon atoms or oxygen atoms are bonded to carbon atoms of the fluororesin film, the adhesion of the silicon-based insulating film 16 to the surface of the fluororesin film 25 is improved.

A first embodiment according to the third manufacturing method of the present invention will be described with reference to FIG. 5, the same components as those described with reference to FIG. 3 are denoted by the same reference numerals.

As shown in FIG. 5A, a silicon oxide film 12 is formed on the substrate 11 to a thickness of, for example, about 500 nm. Next, after forming the wiring 13 on the silicon oxide film 12, a silicon oxide film 14 covering the wiring 13 is formed on the silicon oxide film 12 to a thickness of, for example, 100 nm. The above components are formed in the same manner as described with reference to FIG.

Next, a silane coupling agent (not shown) is applied to the surface of the silicon oxide film 14 by, for example, a spin coating method. This silane coupling agent has the following chemical formula, for example, CF ₃ (CF ₂ ) _n
CH ₂ SiCl ₂ (where n represents an integer of 2 or more),
CF ₃ (CF ₂ ) _n CH ₂ Si (OMe) ₃ (where n
Represents an integer of 2 or more, and Me represents a methyl group) or CF ₃ (CF ₂ ) _n H ₂ Si (OH) ₃ (where n represents an integer of 2 or more). Or for example Me ₃ S
iCl (where Me represents a methyl group), CH ₂ ＣＨCH
Si (OCH ₃ ) ₃ , H ₂ NC ₂ H ₄ NHC ₃ H ₆ Si
(OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₃ CH ₂ CH ₂ Si
MeCl ₂ (where Me represents a methyl group) or C
H ₂ ＣＨCHSiCl ₃ is used. The silane coupling agent described above is an example, and other silane coupling agents can be used.

The silane coupling agent was dissolved in carbon tetrachloride (for example, 1% by weight), and the solution was spin-coated and allowed to stand at room temperature for 1 hour. Thereafter, the substrate was washed with carbon tetrachloride to remove excess unreacted silane coupling agent. Note that in order to shorten the processing time, heat treatment may be performed instead of being left at room temperature for one hour.

Next, a fluororesin film 25 is formed on the silicon oxide film 14 by using, for example, poly (paraxylylene fluoride).
For example, it is formed to a thickness of 500 nm. A general low-pressure CVD apparatus was used as a film forming apparatus, and diparaxylylene fluoride was used as a raw material. At the time of CVD, the above raw material was heated to 200 ° C. to sublimate, decomposed into xylylene monomer at 650 ° C., and introduced on a substrate heated to 150 ° C. As a result, a film of polyxylylene fluoride of about 500 nm was formed.

Alternatively, the fluorocarbon resin film 25 is
The film may be formed by VD. This film formation condition is, for example,
For example, octafluorobutene (C ₄ F ₈ ) gas or tetrafluoroethylene (C ₂ F ₄ ) gas is used as a fluorocarbon-based gas as a process gas, and acetylene (C ₂ H ₂ ) is used to improve heat resistance. Or ethylene (C
₂ H ₄ ). General CVD conditions include plasma power of 500 W, C ₄ F ₈ of 100 sccm,
200sccm the C ₂ H _2, the pressure of the film forming atmosphere 26.
A predetermined pressure and a substrate temperature in a range of 7 Pa to 667 Pa are set to a predetermined temperature in a range of 150 ° C. to 350 ° C.

The fluororesin film 25 may be formed of a material other than the above materials. As an example, a polytetrafluoroethylene resin, a plasma fluorocarbon resin, or the like can be used.

Next, a silane coupling agent is applied to the surface of the fluororesin film 25 by, for example, a spin coating method. This silane coupling agent has the following chemical formula, for example, CF ₃ (CF ₂ ) _n CH ₂ SiC
l ₂ (where n represents an integer of 2 or more), CF ₃ (CF
₂ ) _n CH ₂ Si (OMe) ₃ (where n represents an integer of 2 or more and Me represents a methyl group) or CF ₃ (C
F ₂ ) _n H ₂ Si (OH) ₃ (where n represents an integer of 2 or more) is used. Or, for example, Me ₃ SiCl (where Me represents a methyl group), CH ₂ ＣＨCHSi (OCH
_{3) 3, H 2 NC 2} H 4 NHC 3 H 6 Si (OCH 3)
₃ , CF ₃ (CF ₂ ) ₃ CH ₂ CH ₂ SiMeCl
₂ (where Me represents a methyl group) or CH ₂ ＣC
HSiCl ₃ is used. The silane coupling agent described above is an example, and other silane coupling agents can be used. In this drawing, the fluororesin film 25
The silane coupling agent 31 applied to the surface of is indicated by a two-dot chain line.

Thereafter, as an inert atmosphere, for example, 3
Heat treatment (curing) was performed in a nitrogen (N ₂ ) gas atmosphere at 50 ° C. Here, the heat treatment was performed in a nitrogen atmosphere.
It is also possible to carry out in a rare gas atmosphere.

Next, as shown in FIG. 5B, monosilane (SiH ₄ ) gas and nitrous oxide (N ₂
O) gas and ammonia (NH ₃ ) gas in a reducing atmosphere by PECVD in a fluororesin film 25.
A silicon-based insulating film 16 is formed thereon with a predetermined thickness in the range of 50 nm to 500 nm, for example, using a silicon oxynitride film 16. The film formation conditions are, for example, a flow rate of a monosilane (SiH ₄ ) gas at 100 sccm, a flow rate of a dinitrogen monoxide gas at 1500 sccm, a flow rate of an ammonia gas at 100 sccm, and a flow rate of 1000 sccm using nitrogen as a carrier gas. . Then, the pressure of the film formation atmosphere is set to 102 Pa, and the set temperature of the substrate 11 is set to 350 Pa.
° C and plasma power were set to 500W.

Although a monosilane (SiH ₄ ) gas is used in the above film formation, a higher silane gas such as disilane (Si ₂ H ₆ ) may be used. Although nitrous oxide (N ₂ O) gas was used as an oxygen source, H ₂ O (gas) was used.
It is also possible to use a reducing gas having a nitrogen atom such as hydrazine as a nitrogen source.

Further, dinitrogen monoxide (N
_A silicon nitride film can be formed instead of the silicon oxynitride film 16 by using a monosilane (SiH ₄ ) gas and an ammonia (NH ₃ ) gas except for the ₂ O) gas. In this case, since the relative permittivity of the silicon nitride film is higher than that of the silicon oxynitride film 16, the capacitance between wirings increases. Therefore, a silicon oxide film or a silicon oxynitride film is preferably used.

Next, monosilane (Si
A silicon oxide film 17 is formed on the silicon oxynitride film 16 by bias application high-density plasma CVD using H ₄ ) gas and oxygen (O ₂ ) gas. At this time, for example, the silicon oxide film 17 is formed so that the total thickness of the silicon oxynitride film 16 and the silicon oxide film 17 becomes, for example, 500 nm. The film formation conditions were as follows: the flow rate of a monosilane (SiH ₄ ) gas was 100 sccm, the flow rate of an oxygen gas was 125 sccm, and argon was used as a carrier gas, and the flow rate was 1000 sccm. Further, the pressure of the film formation atmosphere is 1.3 Pa, the set temperature of the substrate 11 is 350 ° C., and the plasma power (microwave power) is 1
kW and bias application power were set to 3 kW. In addition,
When the silicon oxynitride film 16 has a predetermined thickness (for example, 500 nm in this case), the silicon oxide film 17 is not formed.

In the third manufacturing method, the fluorine resin film 2
5 is coated with a silane coupling agent. This silane coupling agent has a molecular structure having a high affinity with the fluororesin film 25 and a molecular structure having a high affinity with the silicon-based insulating film. And the silicon-based insulating film 16 are improved in adhesion. Then, by performing a heat treatment for promoting a crosslinking reaction of the fluororesin film 25, the fluororesin film 25 is polymerized.

In the third manufacturing method, before applying the silane coupling agent, a treatment for giving a physical impact to the surface of the fluororesin film 25 is performed to remove C—F bonds and C—C from the fluororesin film 25. It is also possible to reduce the coupling. The process of giving a physical impact to the surface of the fluororesin film 25 is performed by plasma irradiation, sputtering, ion irradiation, or the like. Here, as an example, the irradiation is performed by plasma irradiation. The plasma processing conditions are the same as the processing conditions for giving a physical impact described with reference to FIG. The processing conditions are set to optimal values depending on the type of the fluororesin. These values are, for example, the values of the fluororesin film 2
It is desirable that the bond of No. 5 be measured by an X-ray photoelectron spectroscopy (XPS) apparatus and set after confirming that the bond with carbon is cut only in a few atomic layers. As a plasma source gas, an inert gas such as a nitrogen (N ₂ ) gas, a helium (He) gas, a neon (Ne) gas, and an argon (Ar) gas is used.

As described above, since the physical shock is applied to the surface of the fluororesin film 25, the CF bonds and CC bonds on the surface of the fluororesin film 25 are broken and reduced. Thus, the reactivity of the surface of the fluororesin film 25 is enhanced. After that, since the silicon-based insulating film 16 is formed on the surface of the fluororesin film 25, the silicon-based insulating film is formed on the surface of the fluororesin film 25 by bonding silicon atoms or oxygen atoms with carbon atoms of the fluororesin film. The adhesion of No. 16 is improved. In the process of giving a physical impact, only the bond with carbon of several atomic layers on the surface of the fluororesin film 25 is destroyed, so that the heat resistance and the relative dielectric constant of the fluororesin film 25 due to the destruction of the CF bond are reduced. Has almost no effect.

The silicon-based insulating film 16 is preferably formed so as to have a Si—H bond at the interface with the fluororesin film 25. The silicon-based insulating film 16 having such a Si—H bond can be formed by the manufacturing method described in the embodiment according to the first invention. That is, the monosilane (S
i—H ₄ ) by plasma CVD using Si—H
The lower layer of the silicon-based insulating film 16 is formed of a film having many bonds. This film has many active dangling bonds and has good adhesion to the base. Subsequently, the film formation in the second step is performed by plasma enhancement CVD in a reducing atmosphere using a monosilane (SiH ₄ ) gas, a dinitrogen monoxide (N ₂ O) gas, and an ammonia (NH ₃ ) gas. An upper layer of the insulating film 16 is formed.

When the silicon-based insulating film 16 is formed, a silicon oxide film or a silicon oxynitride film is formed by adjusting the flow rate of ammonia gas used as a source gas. For example, if the flow rate of ammonia gas is set to 0, the silicon-based insulating film 16 is formed of a silicon oxide film, and if an ammonia gas is used, the silicon-based insulating film 16 is formed of a silicon oxynitride film.

As described above, the silicon-based insulating film 1
6 is formed so as to have a Si—H bond at the interface with the fluororesin film 25, so that the interface of the silicon-based insulating film 16 with the fluororesin film 25 has an active dangling bond. As a result, the atoms of the fluororesin film 25 enter the active dangling bonds, so that the silicon-based insulating film 16
Are formed with good adhesion.

After the surface of the fluororesin film 25 is subjected to a physical shock to break the bond with carbon, the silicon-based insulating film 16 having many Si—H bonds as described above is formed.
Since the silicon atoms or oxygen atoms and the carbon atoms of the fluororesin film 25 are easily bonded to each other, the adhesion of the silicon-based insulating film 16 to the surface of the fluororesin film 25 is further improved.

Next, a second embodiment according to the third manufacturing method of the present invention will be described with reference to FIG. 6, using a process for forming a damascene wiring structure as an example. 6, the same components as those described with reference to FIG. 5 are denoted by the same reference numerals.

As shown in FIG. 6A, after a silicon oxide film 12 is formed on a substrate 11, a silane coupling agent is applied to the surface of the silicon oxide film 12 in the same manner as described with reference to FIG. Is applied. After that, a fluororesin film 25 is formed on the silicon oxide film 12. The above components are formed in the same manner as described with reference to FIG.

Next, as described with reference to FIG. 5A, a silane coupling agent is applied to the surface of the fluororesin film 25 by, for example, a spin coating method. The same silane coupling agent as described above is used. In this drawing, the silane coupling agent 31 applied to the surface of the fluororesin film 25 is indicated by a two-dot chain line.

Then, as an inert atmosphere, for example, 3
Heat treatment (curing) was performed in a nitrogen (N ₂ ) gas atmosphere at 50 ° C. Here, the heat treatment was performed in a nitrogen atmosphere.
It is also possible to carry out in a rare gas atmosphere.

Next, as shown in FIG. 6B, a silicon-based insulating film 16 serving as an etching mask for the fluororesin film 25 is formed on the fluororesin film 25 by a silicon oxide film, a silicon oxynitride film or a nitride film. It is formed of a silicon film. The method for forming the film is the same as the method for forming the silicon-based insulating film 16 described with reference to FIG.

Thereafter, as shown in FIG. 6C, an upper portion of the groove 18 is formed in the silicon-based insulating film 16, and the fluororesin film 25 is etched using the silicon-based insulating film 16 as an etching mask. Thus, a groove 18 is formed.
Next, a barrier metal layer 19 is formed on the inner wall of the groove 18 by, for example, a tantalum nitride film, and then a copper film serving as a seed for copper plating is formed. After the trench 18 is filled with copper by electrolytic copper plating, the excess copper and the tantalum nitride film on the silicon-based insulating film 16 are removed by, for example, CMP to form a wiring 20 made of copper inside the trench 18. The above components are formed in the same manner as described with reference to FIG.

In the above manufacturing method, the fluororesin film 25
Before applying the silane coupling agent to the surface of the substrate, a treatment for giving a physical impact may be performed to reduce the bonding with carbon from the surface of the fluororesin film 25. The treatment method for giving the physical impact is performed by plasma irradiation, sputtering, ion irradiation, or the like.

A first embodiment according to the fourth manufacturing method of the present invention will be described with reference to FIG. 7, the same components as those described with reference to FIG. 5 are denoted by the same reference numerals.

As shown in FIG. 7A, a silicon oxide film 12 is formed on the substrate 11 to a thickness of, for example, about 500 nm. Next, after forming the wiring 13 on the silicon oxide film 12, a silicon oxide film 14 covering the wiring 13 is formed on the silicon oxide film 12 to a thickness of, for example, 100 nm. The above components are formed in the same manner as described with reference to FIG.

Next, in the same manner as described with reference to FIG. 5A, a silane coupling agent is applied to the surface of the silicon oxide film 14 by, for example, a spin coating method. As the silane coupling agent, the same silane coupling agent as that described in the first embodiment in the third manufacturing method can be used.

Next, a fluororesin film 25 is formed on the silicon oxide film 14 using, for example, a polytetrafluoroethylene resin (for example, Teflon AF (trade name) manufactured by DuPont) to a thickness of, for example, 500 nm. I do. The polytetrafluoroethylene resin is not limited to the Teflon AF as long as it has a chemical structure represented by the formula (1).

In this film formation, the fluororesin raw material was dissolved in a fluorocarbon-based solvent, and the viscosity was adjusted to 30 cp. It is applied on the silicon oxide film 14 by a spin coating method to form a thin film having a thickness of 500 nm. The rotation speed at this time was, for example, 3000 rpm.

Next, a baking treatment was performed for 2 minutes in an inert gas atmosphere, for example, a nitrogen gas atmosphere at 100 ° C. and atmospheric pressure to dry the fluororesin film 25.

Next, as shown in FIG. 7B, a silane coupling agent is applied to the surface of the fluororesin film 25 by, for example, a spin coating method. This silane coupling agent has the following chemical formula, for example, CF
₃ (CF ₂ ) _n CH ₂ SiCl ₂ (where n represents an integer of 2 or more), CF ₃ (CF ₂ ) _n CH ₂ Si (OM
e) ₃ (where n represents an integer of 2 or more and Me represents a methyl group) or CF ₃ (CF ₂ ) _n H ₂ Si (O
H) ₃ (where n represents an integer of 2 or more). Or, for example, Me ₃ SiCl (where Me represents a methyl group), CH ₂ ＣＨCHSi (OCH ₃ ) ₃ , H ₂ NC ₂ H
₄ NHC ₃ H ₆ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ )
₃ CH ₂ CH ₂ SiMeCl ₂ (where Me represents a methyl group) or CH ₂ ＣＨCHSiCl ₃ is used. The silane coupling agent described above is an example, and other silane coupling agents can be used. In this drawing, the silane coupling agent 31 applied to the surface of the fluororesin film 25 is indicated by a two-dot chain line.

Thereafter, as an inert atmosphere, for example, 3
Heat treatment (curing) was performed in a nitrogen (N ₂ ) gas atmosphere at 50 ° C. Here, the heat treatment was performed in a nitrogen atmosphere.
It is also possible to carry out in a rare gas atmosphere.

Next, as shown in FIG. 7C, monosilane (SiH ₄ ) gas and nitrous oxide (N ₂
O) gas and ammonia (NH ₃ ) gas by plasma enhancement CVD in a reducing atmosphere.
On the fluororesin film 25, a silicon oxynitride film 16 is formed as a silicon-based insulating film to a predetermined thickness in the range of, for example, 50 nm to 500 nm. The film forming conditions were as follows: the flow rate of a monosilane (SiH ₄ ) gas was 100 sccm, the flow rate of a nitrous oxide gas was 1500 sccm, the flow rate of an ammonia gas was 100 sccm, and nitrogen was used as a carrier gas and the flow rate was 1000 sccm. Then, the pressure of the film formation atmosphere is set to 102 Pa, and the set temperature of the substrate 11 is set to 35.
The temperature was set to 0 ° C. and the plasma power was set to 500 W.

Although a monosilane (SiH ₄ ) gas is used in the above film formation, a higher silane gas such as disilane (Si ₂ H ₆ ) can be used. Although nitrous oxide (N ₂ O) gas was used as an oxygen source, H ₂ O (gas) was used.
It is also possible to use a reducing gas having a nitrogen atom such as hydrazine as a nitrogen source.

Further, dinitrogen monoxide (N
_A silicon nitride film can be formed instead of the silicon oxynitride film 16 by using a monosilane (SiH ₄ ) gas and an ammonia (NH ₃ ) gas except for the ₂ O) gas. In this case, since the relative permittivity of the silicon nitride film is higher than that of the silicon oxynitride film 16, the capacitance between wirings increases. Therefore, a silicon oxide film or a silicon oxynitride film is preferably used.

Next, monosilane (Si
A silicon oxide film 17 is formed on the silicon oxynitride film 16 by bias application high-density plasma CVD using H ₄ ) gas and oxygen (O ₂ ) gas. At this time, for example, the silicon oxide film 17 is formed so that the total thickness of the silicon oxynitride film 16 and the silicon oxide film 17 becomes, for example, 500 nm. The film formation conditions were as follows: the flow rate of a monosilane (SiH ₄ ) gas was 100 sccm, the flow rate of an oxygen gas was 125 sccm, and argon was used as a carrier gas, and the flow rate was 1000 sccm. Further, the pressure of the film formation atmosphere is 1.3 Pa, the set temperature of the substrate 11 is 350 ° C., and the plasma power (microwave power) is 1
kW and bias application power were set to 3 kW. In addition,
When the silicon oxynitride film 16 has a predetermined thickness (for example, 500 nm in this case), the silicon oxide film 17 is not formed.

In the fourth manufacturing method, the fluorine resin film 2
Since 5 is formed by coating, the solvent in the fluororesin film 25 formed by coating is evaporated by drying the fluororesin film 25 by baking. After that, a silane coupling agent is applied to the surface of the fluororesin film 25. This silane coupling agent is a fluororesin film 2
5 and a molecular structure having a high affinity with the silicon-based insulating film 16, the fluorinated resin film 25 and the silicon-based insulating film 16 can be connected via the silane coupling agent. Adhesion is enhanced. Moreover, since the silane coupling agent is applied in a state where the solvent in the fluororesin film 25 is evaporated, that is, in a state where the network of the fluororesin 25 is incomplete, a heat treatment for promoting crosslinking is performed. Since the crosslinking with the silane coupling agent also proceeds at the same time as the crosslinking of the film 25 proceeds, the adhesiveness is further improved. Then, as the crosslinking proceeds, the fluororesin film 25 is polymerized.

In the fourth manufacturing method, after performing the baking process and before applying the silane coupling agent, a process of giving a physical impact to the surface of the fluororesin film 25 is performed to remove carbon from the fluororesin film 25. It is also possible to reduce the coupling with. The process of giving a physical impact to the surface of the fluororesin film 25 is performed by plasma irradiation, sputtering, ion irradiation, or the like. Here, as an example,
This is performed by plasma irradiation. The plasma processing conditions are the same as the processing conditions for giving a physical impact described with reference to FIG. The processing conditions are set to optimal values depending on the type of the fluororesin. In addition, these values can be set by measuring the bond of the fluororesin film 25 using, for example, an X-ray photoelectron spectroscopy (XPS) device and confirming that, for example, only a few atomic layers have broken the C—F bond. desirable. The plasma source gas includes nitrogen (N ₂ ) gas, helium (He) gas, neon (Ne) gas, and argon (A
r) Use an inert gas such as a gas.

As described above, since the treatment for giving a physical impact to the surface of the fluororesin film 25 is performed, the bond with carbon on the surface of the fluororesin film 25 is broken and reduced. Surface reactivity is increased.
Then, the silicon-based insulating film 1 is formed on the surface of the fluororesin film 25.
By forming 6, silicon atoms and oxygen atoms are bonded to carbon atoms of the fluororesin film, whereby the adhesion of the silicon-based insulating film 16 to the surface of the fluororesin film 25 is improved. In the process of giving the physical impact, only the bond with carbon of several atomic layers on the surface of the fluororesin film 25 is broken, so that the heat resistance and the relative dielectric constant of the fluororesin film 25 due to the destruction of the CF bond are reduced. Has almost no effect.

The silicon-based insulating film 16 may be formed so as to have a Si—H bond at the interface with the fluororesin film 25. The silicon-based insulating film 16 having such a Si—H bond can be formed by the manufacturing method described in the embodiment according to the first invention. That is, in the film formation in the first step, the lower layer of the silicon-based insulating film 16 is formed of a film having many Si—H bonds by plasma CVD mainly containing monosilane (SiH ₄ ). This film has many active dangling bonds and has good adhesion to the base. Subsequently, the film formation in the second step is performed using monosilane (S
An upper layer of the silicon-based insulating film 16 is formed by PECVD in a reducing atmosphere using iH ₄ ) gas, dinitrogen monoxide (N ₂ O) gas, and ammonia (NH ₃ ) gas.

When the silicon-based insulating film 16 is formed, a silicon oxide film or a silicon oxynitride film is obtained by adjusting the flow rate of ammonia gas used as a source gas. For example, if the flow rate of ammonia gas is set to 0, the silicon-based insulating film 16 is formed of a silicon oxide film, and if an ammonia gas is used, the silicon-based insulating film 16 is formed of a silicon oxynitride film.

As described above, the silicon-based insulating film 1
6 is formed so as to have a Si—H bond at the interface with the fluororesin film 25, so that the interface of the silicon-based insulating film 16 with the fluororesin film 25 has an active dangling bond. As a result, the atoms of the fluororesin film 25 enter the active dangling bonds, so that the silicon-based insulating film 16
Are formed with good adhesion.

After the surface of the fluororesin film 25 is subjected to a physical impact to break the bond with carbon, the silicon-based insulating film 16 having a large number of Si—H bonds as described above is formed.
Since the silicon atoms or oxygen atoms and the carbon atoms of the fluororesin film 25 are easily bonded to each other, the adhesion of the silicon-based insulating film 16 to the surface of the fluororesin film 25 is further improved.

Next, a second embodiment according to the fourth manufacturing method of the present invention will be described with reference to FIG. 8, using a process for forming a damascene wiring structure as an example. 8, the same components as those described with reference to FIG. 7 are denoted by the same reference numerals.

As shown in FIG. 8A, a silicon oxide film 12 is formed on a substrate 11 in the same manner as described with reference to FIG. As described above, a silane coupling agent is applied to the surface of the silicon oxide film 12. Further, a fluororesin film 25 is formed on the silicon oxide film 12 by a coating method.
Is formed to a thickness of, for example, 500 nm using, for example, a polytetrafluoroethylene-based resin (for example, Teflon AF (trade name) manufactured by DuPont). The polytetrafluoroethylene resin is not limited to the Teflon AF as long as it has a chemical structure represented by the formula (1).

Thereafter, baking treatment was performed for 2 minutes in an inert gas atmosphere, for example, a nitrogen gas atmosphere at 100 ° C. and atmospheric pressure.

Subsequently, as shown in FIG. 8 (2),
A silane coupling agent is applied to the surface of the fluororesin film 25 by, for example, a spin coating method. As the silane coupling agent, the same silane coupling agent as described in (2) of (7) can be used. In this drawing, the silane coupling agent 31 applied to the surface of the fluororesin film 25 is indicated by a two-dot chain line.

Thereafter, as an inert atmosphere, for example, 3
Heat treatment (curing) was performed in a nitrogen (N ₂ ) gas atmosphere at 50 ° C. Here, the heat treatment was performed in a nitrogen atmosphere.
It is also possible to carry out in a rare gas atmosphere.

Next, as shown in FIG. 8C, a silicon-based insulating film 16 serving as an etching mask for the fluororesin film 25 is formed on the fluororesin film 25 by a silicon oxide film, a silicon oxynitride film, or a nitride film. It is formed of a silicon film. The film formation method can be performed in the same manner as the method of forming the silicon-based insulating film 16 described with reference to FIG.

Thereafter, as shown in FIG. 8D, an upper portion of the groove 18 is formed in the silicon-based insulating film 16 in the same manner as described with reference to FIG. The groove 18 is formed by etching the fluororesin film 25 using the film 16 as an etching mask. Next, a barrier metal layer 19 is formed on the inner wall of the groove 18 by, for example, a tantalum nitride film, and then a copper film serving as a seed for copper plating is formed. After the trench 18 is filled with copper by electrolytic copper plating, the excess copper and the tantalum nitride film on the silicon-based insulating film 16 are removed by, for example, CMP to form a wiring 20 made of copper inside the trench 18.

In this manufacturing method, after the baking treatment and before the application of the silane coupling agent, a treatment for giving a physical impact to the surface of the fluororesin film 25 is performed to remove carbon from the surface of the fluororesin film 25. May be reduced. The method of giving the physical impact is performed by plasma irradiation, sputtering, ion irradiation, or the like.

The organic insulating film 1 described in each of the above embodiments
5 and the fluororesin film 25 can also be formed of a material having a chemical structure represented by the formula (2). As an example, there is a cyclo-polymerized florated polymer resin [for example, Cytop (trade name)].

[0117]

Embedded image

In this film formation, the above-mentioned material was dissolved in a fluorocarbon-based solvent, and the viscosity was adjusted to 30 cp. It is applied on the silicon oxide film 14 by a spin coating method,
A thin film having a thickness of 00 nm is formed. The rotation speed at this time was, for example, 3000 rpm. Subsequently, a baking treatment was performed for 2 minutes in an inert gas atmosphere, for example, a nitrogen gas atmosphere at 100 ° C. and atmospheric pressure. Further, as an inert atmosphere, for example, heat treatment (curing) was performed in a nitrogen (N ₂ ) gas atmosphere at 350 ° C. Here, the heat treatment is performed in a nitrogen atmosphere, but may be performed in a rare gas atmosphere.

Alternatively, the organic insulating film 15 and the fluororesin film 25 described in each of the above embodiments can be formed of a material having a chemical structure represented by the formula (3). One example is a fluorinated polyallyl ether-based resin [for example, FLARE (trade name)].

[0120]

Embedded image

This film formation is almost the same as the above-mentioned method for producing the cyclopolymerized fluoropolymerized polymer resin except that a fluoropolyallyl ether resin is used as a material to be dissolved in a fluorocarbon solvent.

Alternatively, the organic insulating film 15 and the fluororesin film 25 described in each of the above embodiments can be formed of a fluorinated polyimide resin.

This film is formed by the low pressure CVD method in the same manner as the film formation of the above-mentioned polyparaxylylene fluoride.
Alternatively, as described above, a film is formed by dissolving in a fluorocarbon-based solvent by a spin coating method, and then performing a baking process. In any of the above cases, heat treatment (curing) is performed in a nitrogen (N ₂ ) gas atmosphere at 350 ° C., for example, as an inert atmosphere. This heat treatment can be performed in a rare gas atmosphere.

As described above, the organic insulating film 15 and the fluororesin film 25 can be formed of various low dielectric constant organic films. In addition to the materials described above, the relative dielectric constant is 3.5 or less. It is also possible to form with a low dielectric constant organic film.

The film thickness of each film described in each of the above embodiments,
The film forming conditions and the like are merely examples, and are not limited to the values described above, and an optimal value or an optimal range is appropriately selected.

By improving the adhesion between the organic insulating film (fluororesin) and the silicon-based insulating film by the various manufacturing methods described in the above embodiments, the fluororesin can be introduced into the semiconductor device process. become.

In the above description, the method of forming the silicon-based insulating film 16 on the organic insulating film 15 or the fluororesin film 25 has been described. However, these are methods used in a part of the semiconductor device manufacturing process. Before and after this, a transistor forming step, a wiring forming step, and the like are performed. In the above embodiment, the wiring 13 is formed on the silicon oxide film 12 on the substrate 11 and the silicon oxide film 14 covering the wiring 13 is formed, and the silicon oxide film 12 and the fluororesin film 25 are formed on the substrate 12. After forming the above, an example is shown in which the wiring 20 serving as a so-called trench wiring is formed in the fluororesin film 25. However, on the substrate 11, formation of an active region, formation of a lower insulating film, formation of a lower wiring, and the like are performed. The silicon oxide film 12 can be formed so as to cover them. The wiring 13 or the wiring 20 is a silicon oxide film 1
2 can be connected to the lower layer wiring. Further, an upper wiring is further formed on the wiring 13 or the wiring 20 via an insulating film.

In FIGS. 1, 3, 5 and 7,
Although the silicon oxide film 14 covering the wiring 13 is shown, the silicon oxide film 14 is not formed, and the organic insulating film 15 is formed in the case of FIG. 1 and the fluororesin film is formed in the cases of FIGS. 3, 5, and 7. It is also possible to form 25.

[0129]

As described above, according to the first manufacturing method of the present invention, the silicon-based insulating film is formed so as to have a Si-H bond at the interface with the organic insulating film.
The active dangling bond generated by the H bond enables the silicon-based insulating film to be formed with good adhesion to the organic insulating film.

According to the second manufacturing method of the present invention, since the treatment for giving a physical impact to the surface of the fluororesin film is performed, the bond with carbon is broken and reduced, and the reactivity of the surface of the fluororesin film is reduced. Increase. Therefore, the silicon-based insulating film can be formed with good adhesion to the fluororesin film.

According to the third production method of the present invention, since the silane coupling agent is applied to the surface of the fluororesin film,
The adhesion between the fluororesin film and the silicon-based insulating film can be increased via the silane coupling agent.

According to the fourth manufacturing method of the present invention, the silane coupling agent is formed on the surface of the fluororesin film after the fluororesin film is formed by coating and dried, and before the heat treatment for promoting crosslinking is performed. Is applied, so that the adhesion between the fluororesin film and the silicon-based insulating film can be enhanced via the silane coupling agent, and at the same time as the crosslinking of the fluororesin film progresses, the crosslinking with the silane coupling agent also proceeds. Since it can be advanced, the adhesion can be further improved.

[Brief description of the drawings]

FIG. 1 is a manufacturing process diagram for explaining a first embodiment according to a first manufacturing method of the present invention.

FIG. 2 is a manufacturing process diagram for explaining a second embodiment according to the first manufacturing method of the present invention.

FIG. 3 is a manufacturing process diagram for explaining a first embodiment according to a second manufacturing method of the present invention.

FIG. 4 is a manufacturing process diagram for explaining a second embodiment according to the second manufacturing method of the present invention.

FIG. 5 is a manufacturing process diagram for explaining a first embodiment according to a third manufacturing method of the present invention.

FIG. 6 is a manufacturing process diagram for explaining a second embodiment according to the third manufacturing method of the present invention.

FIG. 7 is a manufacturing process diagram for explaining a first embodiment according to a fourth manufacturing method of the present invention.

FIG. 8 is a manufacturing process diagram for explaining a second embodiment according to the fourth manufacturing method of the present invention.

[Explanation of symbols]

 15: Organic insulating film, 16: Silicon-based insulating film

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5F033 HH09 HH11 HH21 HH32 MM01 PP15 PP27 QQ00 QQ14 QQ28 QQ54 QQ74 RR04 RR06 RR08 RR21 RR23 RR24 SS01 SS02 SS04 SS11 SS13 SS15 SS22 TT04 XX12 5F010 AD10 AF01 AD01 AF01 AG07 AH02

Claims (11)

[Claims] When forming a silicon-based insulating film made of a silicon oxide film, a silicon oxynitride film, or a silicon nitride film on a surface of an organic insulating film, an interface of the silicon-based insulating film with the organic insulating film is formed by Si
A method for manufacturing an insulating film, wherein the insulating film is formed so as to have an -H bond. 2. a step of performing a process of giving a physical impact to the surface of the fluororesin film to reduce the bonding with carbon on the surface of the fluororesin film; and a process of applying the physical impact to the fluororesin film. Forming a silicon-based insulating film made of a silicon oxide film, a silicon oxynitride film or a silicon nitride film on the surface of the insulating film. 3. The method according to claim 2, wherein an interface between the silicon-based insulating film and the fluororesin film is formed to have a Si—H bond. 4. A step of applying a silane coupling agent to the surface of the fluororesin film, a step of performing a heat treatment to promote a crosslinking reaction of the fluororesin film, and a step of applying the silane coupling agent to the fluororesin film Forming a silicon-based insulating film made of a silicon oxide film, a silicon oxynitride film or a silicon nitride film on the surface of the insulating film. 5. A process for giving a physical impact to the surface of the fluororesin film on which the silicon-based insulating film is formed, before applying the silane coupling agent, so that carbon on the surface of the fluororesin film is 5. The method for manufacturing an insulating film according to claim 4, wherein coupling with the insulating film is reduced. 6. The method according to claim 4, wherein an interface between the silicon-based insulating film and the fluororesin film is formed to have a Si—H bond. 7. The method according to claim 5, wherein an interface between the silicon-based insulating film and the fluororesin film is formed to have a Si—H bond. 8. a step of applying a fluororesin on a substrate to form a fluororesin film, a step of drying the fluororesin film, and a step of applying a silane coupling agent to the surface of the fluororesin film; A step of performing a heat treatment for accelerating a crosslinking reaction of the fluororesin film; and a silicon-based insulating film made of a silicon oxide film, a silicon oxynitride film or a silicon nitride film on the surface of the fluororesin film on which the silane coupling agent has been applied. Forming an insulating film. 9. A process for applying a physical impact to the surface of the fluororesin film on which the silicon-based insulating film is to be formed after drying the fluororesin film and before applying the silane coupling agent. 9. The method according to claim 8, wherein bonding to carbon on the surface of the fluororesin film is reduced. 10. The method according to claim 8, wherein an interface between the silicon-based insulating film and the fluororesin film is formed to have a Si—H bond. 11. The method according to claim 9, wherein an interface between the silicon-based insulating film and the fluororesin film has a Si—H bond.