JP2005203569A - Fabrication process of semiconductor device and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To strike a balance between adhesiveness and diffusion preventive properties of a barrier metal, and to improve controllability of composition in the film thickness direction. <P>SOLUTION: The fabrication process of a semiconductor device comprises a step for forming a TaN film on a substrate using Ta[N(CH<SB>3</SB>)<SB>2</SB>]<SB>5</SB>gas and NH<SB>3</SB>gas for reducing the Ta[N(CH<SB>3</SB>)<SB>2</SB>]<SB>5</SB>gas, and a step for forming a Ta film on the TaN film formed by the TaN film forming step using the Ta[N(CH<SB>3</SB>)<SB>2</SB>]<SB>5</SB>gas and He/H<SB>2</SB>gas for reducing the Ta[N(CH<SB>3</SB>)<SB>2</SB>]<SB>5</SB>gas without exposing the substrate to the atmosphere. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a semiconductor device or a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor element device having an interlayer insulating film and using Cu (copper) wiring.

In recent semiconductor devices typified by the 65 nm node generation, the delay of signal propagation in the wiring determines the device operation. The delay constant in wiring is represented by the product of wiring resistance and wiring capacitance. For this reason, in order to reduce the wiring resistance and speed up the device operation, a material having a relative dielectric constant smaller than that of conventional SiO ₂ is used as the material of the interlayer insulating film, and Cu (copper) having a small specific resistance as the wiring material. Is being used.

  Cu multilayer wiring is often formed by a damascene method.

FIG. 15 is a process cross-sectional view illustrating a main part of the damascene method.
That is, first, as shown in FIG. 2A, an interlayer insulating film 220 is formed on a base body 200 such as a silicon (Si) substrate. Next, as illustrated in FIG. 15B, an opening H is formed in the interlayer insulating film 220. The opening H serves as a wiring groove for a wiring layer and a via hole for a via. Next, as shown in FIG. 15C, the barrier metal layer 240 is formed on the inner wall of the opening H. Further, as shown in FIG. 15D, a Cu layer 260 is embedded as a wiring material. Here, in embedding the Cu layer 260, first, Cu is deposited in a thin film by a method such as physical vapor deposition (PVD), and the Cu thin film is buried as a cathode electrode by an electrolytic plating method or the like. Are often implemented.

  In the damascene method, after depositing the barrier metal layer 240 and the Cu layer 260, the barrier metal layer 240 and the Cu layer 260 deposited outside the opening H are subjected to chemical mechanical polishing (chemical mechanical polishing). : CMP) to form a buried structure as shown in FIG.

Here, the barrier metal layer 240 has a role of preventing Cu diffusion to the base 200 such as a silicon substrate, improving adhesion between the interlayer insulating film 220 and the Cu layer 260, and preventing oxidation of the Cu layer 260. .
Non-Patent Documents 1 and 2 or Patent Document 1 can be cited as documents disclosing a wiring structure using an interlayer insulating film as described above.
K. Maex, MR Baklanov, D. Shamiryan, F. Iacopi, SHBrongersma, ZSYanovitskaya, Journal of Applied Physics 93 (11), pp.8793-8841, 2003. W. Besling, A. Satta, J. Schuhmacher, T. Abell, V. Sutcliffe, A.-M. Hoyas, G. Beyer, D. Gravesteijn, K. Maex, Proceedings of IEEE 2002 International Interconnect Technology Conference, pp. 288-291 JP 2002-359243 A

  In recent years, it has been studied to reduce the wiring resistance and via resistance by thinning the barrier metal. Currently, the most frequently studied method for forming a barrier metal is a laminated film in which polycrystalline Ta (tantalum) is formed on amorphous TaN (tantalum nitride) by PVD. Amorphous TaN which does not have a grain boundary which becomes a high-speed diffusion path of Cu prevents diffusion of Cu into the interlayer insulating film, and ensures adhesion with Cu by Ta. The PVD method is currently the mainstream as a barrier metal forming method, but the coverage on the pattern side wall at the minimum dimension is as bad as 30% or less, and the film thickness on the field is 10 nm or more for TaN and Ta, respectively. Often becomes. That is, it is difficult to form a barrier metal having a film thickness smaller than 10 nm. Even if the barrier metal is thinned, when the PVD method is used, the coverage is poor and the film thickness on the side wall of the wiring groove or via hole is still thin. It becomes impossible to secure the property and adhesion.

  Therefore, it is required to form a barrier metal by a chemical vapor deposition (CVD) method, which can easily form a thin film with a higher coverage than the PVD method. In recent years, barrier metals have been developed by an atomic layer deposition (ALD) method, which is a kind of CVD method, and is easier to obtain a film having a uniform and better film property than conventional CVD methods. In the ALD method, for example, a raw material 1 containing an element A is irradiated onto a substrate and saturatedly adsorbed, and then a raw material 2 containing an element B is irradiated onto the substrate and saturatedly adsorbed, whereby a compound AB of an element A and an element B is obtained. Therefore, the film thickness uniformity, the composition uniformity, the film thickness controllability, and the film property are superior to those of the conventional CVD method. For this reason, it is possible to form a barrier metal having a coating ratio of 90% or more and a film thickness smaller than 10 nm, which is difficult with the conventional CVD method. Currently, as a barrier metal formed by the ALD method, nitriding of high melting point metals such as TaN (tantalum nitride), TaCN (tantalum carbonitride), WN (tungsten nitride), WCN (tungsten carbonitride), TiN (titanium nitride), etc. Films or carbon nitride films have been reported.

However, a refractory metal nitride film formed by the ALD method has a problem of poor adhesion while being excellent in Cu diffusion prevention. Wiring formation is difficult because of poor adhesion. Therefore, the wiring reliability is lowered. It is difficult to achieve both adhesion and diffusion prevention with a single layer film. In order to achieve both adhesion and anti-diffusion properties, it is desirable to control the composition in the film thickness direction to form a multilayer film. However, since the ALD method is formed by a saturated adsorption mechanism, it is determined as described above. It is easy to obtain films with different compositions, but it is difficult to obtain films with different compositions. That is, in the ALD method, since it is difficult to form a thin film in which the composition ratio of the metal element and nitrogen is controlled, it is difficult to form a laminated structure thin film.
Therefore, controlling the composition in the film thickness direction in a barrier metal formed by the ALD method is an issue in developing an ultra-thin barrier metal having a film thickness smaller than 10 nm.

An object of this invention is to make the adhesiveness and diffusion prevention property of a barrier metal compatible. Another object of the present invention is to improve the controllability of the composition in the film thickness direction.
It is another object of the present invention to provide a semiconductor device that achieves both barrier metal adhesion and diffusion prevention.

A method for manufacturing a semiconductor device according to the present invention includes:
A first barrier metal thin film forming step of forming a first barrier metal thin film on the substrate using a first gas and a second gas for reducing the first gas;
A fourth gas that reduces the third gas and the third gas on the first barrier metal thin film formed by the first barrier metal thin film forming step without exposing the substrate to the atmosphere. And a second barrier metal thin film forming step of forming a second barrier metal thin film using

  By forming the second barrier metal thin film on the first barrier metal thin film using the third gas and the fourth gas for reducing the third gas, the thickness of the barrier metal is increased. The composition is controlled to form a multilayer film. In addition, the first barrier metal thin film is not oxidized by forming the second barrier metal thin film without exposing the substrate to the atmosphere.

In addition, the first barrier metal thin film forming step includes
A first gas supply step of supplying the first gas to the substrate;
A second gas supply step for supplying the second gas to the substrate after the first gas supply step;
In the first barrier metal thin film forming step, by repeating the first gas supply step and the second gas supply step, a first barrier metal thin film having a predetermined thickness is formed,
The second barrier metal thin film forming step includes
A third gas supply step for supplying the third gas to the substrate after the second gas supply step;
A fourth gas supply step for supplying the fourth gas to the substrate after the third gas supply step;
In the second barrier metal thin film forming step, by repeating the third gas supply step and the fourth gas supply step, the first barrier metal thin film having a thickness larger than that of the first barrier metal thin film having the predetermined thickness is obtained. 2 barrier metal thin films are formed.

  After the first gas supply step, the second gas for reducing the first gas is supplied to the substrate, a thin film at an atomic layer level is formed, and the first barrier metal thin film is desired by repeating. It becomes possible to form in the film thickness which does. Further, after the second gas supply step, that is, after the formation of the first barrier metal thin film, the third gas is supplied to the base, and then the fourth gas is supplied to the base. By forming and repeating a thin film at the atomic layer level, a second barrier metal thin film having a different composition can be formed on the first barrier metal thin film in a desired film thickness. Further, by forming a second barrier metal thin film having a thickness larger than that of the first barrier metal thin film having the predetermined thickness, the first barrier metal thin film can be prevented from diffusing with Cu, and the second barrier metal thin film can be prevented. A metal thin film is used for improving adhesion with Cu.

  In the first and second barrier metal thin film forming steps, the first and second barrier metal thin films are formed using atomic layer vapor deposition.

  Since the atomic layer vapor deposition method is used, it is possible to form the second barrier metal thin film at the atomic layer level having a different composition on the first barrier metal thin film at the atomic layer level.

  In the second barrier metal thin film forming step, the substrate is exposed to a plasma atmosphere of the fourth gas supplied in the fourth gas supply step. By exposing the substrate to a plasma atmosphere of a fourth gas, the third gas is reduced by radicals of the fourth gas.

In addition, an insulating film using a porous insulating material is formed on the base,
In the first barrier metal thin film forming step, the first barrier metal thin film is formed on a surface of the insulating film.

  A first barrier metal thin film is formed on an insulating film which needs to be prevented from diffusing into a hole, which is a porous insulating material.

In the first barrier metal thin film forming step, a metal nitride film is formed as the first barrier metal thin film,
In the second barrier metal thin film forming step, a metal film having a nitrogen concentration lower than that of the first barrier metal thin film is formed as the second barrier metal thin film.

  By forming a metal film having a lower nitrogen concentration than the first barrier metal thin film as the second barrier metal thin film, the conductivity is formed after the first barrier metal thin film having a higher nitrogen concentration. Adhesion with the material is improved.

A semiconductor device according to the present invention includes:
An insulating layer using an insulating material disposed on the substrate;
A wiring portion using a wiring material disposed in the insulating layer;
It is provided with the 1st and 2nd barrier metal thin film part with which the minimum dimension of each film thickness arrange | positioned between the said wiring part and the said insulating material was formed smaller than 10 nm.

  Since the first and second barrier metal thin film portions are provided, the composition of the barrier metal in the film thickness direction is a multilayer film. In addition, since the minimum dimension of each film thickness of the first and second barrier metal thin film portions is smaller than 10 nm, wiring resistance and via resistance are reduced as compared with the conventional case.

  According to the present invention, the composition of the barrier metal in the film thickness direction can be controlled to form a multilayer film, and a barrier metal having adhesion and diffusion prevention can be formed. Further, it is possible to prevent the first barrier metal thin film from being insulative due to oxidation, and to form the first barrier metal thin film as a conductive film.

  As will be described later, the film thickness necessary for improving the adhesion with Cu is larger than the film thickness necessary for preventing diffusion with Cu. According to the present invention, a second barrier metal thin film having a different composition can be formed on the first barrier metal thin film, the first barrier metal thin film is used for preventing diffusion with Cu, and the second barrier metal thin film is used. A barrier metal thin film can be used to improve adhesion to Cu.

  According to the present invention, since the atomic layer vapor deposition method is used, it is possible to form the second barrier metal thin film at the atomic layer level having a different composition on the first barrier metal thin film at the atomic layer level. And an ultra-thin barrier metal can be formed. Furthermore, it is superior in film thickness uniformity, composition uniformity, film thickness controllability, and coating properties as compared with conventional CVD methods. For this reason, it is possible to form each barrier metal layer having a coating rate of 90% or more and a film thickness smaller than 10 nm, which is difficult with the conventional CVD method.

  According to the present invention, by using plasma, a film in which a nitriding component or a carbonizing component, which has been difficult in the conventional ALD method, is removed by the radical of the fourth gas even when an organometallic compound is used as the third gas, can be obtained. Can be obtained. Furthermore, even when nitrogen is contained in the fourth gas, the ratio of the nitriding component entering into the second barrier metal thin film by the third and fourth gases is reduced to obtain a film that suppresses the nitriding component. Can do.

  According to the present invention, the first and second barrier metal thin films are formed on the insulating film which needs to be prevented from diffusing into the holes, which is a porous insulating material. If Cu adhesion and diffusion prevention can be improved, a porous dielectric material having a low dielectric constant can be used for the insulating film. Since a porous dielectric material having a low dielectric constant can be used for the insulating film, the capacitance between wirings can be reduced. Since the inter-wiring capacitance can be reduced, the delay constant in the wiring can be reduced. Therefore, the device operation can be speeded up.

  According to the present invention, as the second barrier metal thin film, a metal film having a nitrogen concentration lower than that of the first barrier metal thin film is formed, thereby preventing diffusion with the first barrier metal thin film having a high nitrogen concentration. And the adhesion can be improved with the second barrier metal thin film.

  According to the present invention, it is possible to obtain a semiconductor device provided with a barrier metal having adhesion and diffusion prevention by using a multilayer film having adhesion and diffusion prevention. Moreover, since the minimum dimension of each film thickness of the 1st and 2nd barrier metal thin film part is smaller than 10 nm, wiring resistance and via | veer resistance can be reduced compared with the past.

  First, the inventors tried a method of controlling the composition by irradiating the substrate with an organometallic compound after forming the first barrier metal film by the ALD method. It has been found that there are cases where adhesion is not sufficiently improved. Since the adhesion is not improved, the conductivity is also deteriorated. In addition, since the organometallic raw material used for the ALD method does not adsorb one or more molecular layers stably on the substrate unless it is irradiated with a reducing or oxidizing raw material, it is difficult to increase the film thickness to a desired thickness. I found out. Moreover, when an oxidizing raw material was irradiated, it became an insulating film, and it discovered that the barrier metal film which it would like to use as a electrically conductive film cannot be obtained.

Embodiment 1 FIG.
FIG. 1 is a flowchart showing the main part of the semiconductor device manufacturing method according to the first embodiment. FIG. 1 particularly shows a process for forming a barrier metal.
In FIG. 1, in the present embodiment, Ta [N (CH ₃ ) ₂ ] ₅ (pentadimethylamidotalium) and Ar (argon) are used to form a TaN film as a first barrier metal film. supplying _{Ta [N (CH 3) 2} ] 5, Ar supplying step (S102), Ar supplying step of supplying an Ar (S104), NH ₃ supply step (S106) for supplying the NH ₃ (ammonia), supplying Ar A series of steps called Ar supply step (S108) is performed one round or two or more rounds. That is, the series of steps is performed at least once.
Then, in order to form a Ta film as the second barrier metal film, Ta [N (CH ₃ ) ₂ ] ₅ and Ar [N (CH ₃ ) ₂ ] ₅ and Ar supply step (S110) are supplied. ), Ar supply process for supplying Ar (S112), He / H ₂ supply process for supplying He (helium) and H ₂ (hydrogen) (S114), Ar supply process for supplying Ar (S116) The process is carried out a plurality of times such as one round or two rounds. That is, the series of steps is performed at least once.

FIG. 2 is a process sectional view showing a process performed corresponding to the flowchart of FIG.
In FIG. 2, a Ta [N (CH ₃ ) ₂ ] ₅ , Ar supply process is used as a first barrier metal thin film forming process for forming the TaN film (which is an example of the first barrier metal thin film) in FIG. The process from (S102) to the Ar supply process (S108) is shown. Subsequent steps will be described later. The first barrier metal thin film forming step is performed using atomic layer vapor deposition.

First, as a premise, an SiC insulating film 11 using SiC as an example of an insulating material on a substrate 10 and a porous insulating material (an example of an insulating material) formed on the SiC insulating film 11 are described. An insulating film 15 is formed which includes a porous insulating film 12 using (a) and a SiO ₂ insulating film 13 using SiO ₂ (which is an example of an insulating material) formed on the porous insulating film 12. .
Further, an opening 50 for depositing a conductive material described later is formed in the base 10. The opening 50 may be formed by, for example, forming a resist mask (not shown), etching the exposed insulating film, and then removing the resist mask by a method such as ashing.

By forming the SiC insulating film 11 using SiC, it becomes an etching stopper when the opening 50 is formed. In addition, as the material of the porous insulating film 12, for example, porous methyl silsequioxane (MSQ) having a low relative dielectric constant can be used. As the formation method, for example, a spin-on-glass (SOG) method in which a thin film is formed by spin-coating a solution and heat-treating can be used. A porous insulating film having a predetermined physical property value can be obtained by appropriately adjusting the MSQ material, formation conditions, and the like. For example, the porous insulating film 12 having the following physical property values is obtained.

Density: 0.68 g / cm ³
Porosity: 54%
Maximum value of pore diameter distribution: 1.9 nm
Relative permittivity: 1.81
Elastic modulus: 1.6 GPa
Hardness: 0.1 GPa

In FIG. 2A, as the Ta [N (CH ₃ ) ₂ ] ₅ , Ar supply process (which is an example of the first gas supply process), the Ta 10 is formed on the base 10 having the insulating film 15 formed on the upper surface. A mixed gas of [N (CH ₃ ) ₂ ] ₅ and Ar (an example of a first gas) is supplied. The mixed gas of Ta [N (CH ₃ ) ₂ ] ₅ and Ar is supplied to the substrate 10 so that the substrate 10 is irradiated from above the substrate 10. Said _{Ta [N (CH 3) 2} ] that a gas mixture of ₅ and Ar are irradiated to the substrate 10, Ta on the substrate 10 surface and the inner surface of the opening portion 50 (the inner _{wall) [N (CH 3) 2} ] ₅ is adsorbed. Adsorption is saturated adsorption.

In FIG. 2B, the Ar gas is supplied to the substrate 10 as an Ar supply step. The Ar gas is supplied to the base 10 so that the base 10 is irradiated from above the base 10. By irradiating the base 10 with the Ar gas, the atmosphere around the surface of the base 10 and the opening 50 is replaced. By substitution, Ta [N (CH ₃ ) ₂ ] ₅ more than necessary can be removed.

In FIG. 2C, as the NH ₃ supply step (which is an example of the second gas supply step), the Ta [N (CH ₃ ) ₂ ] ₅ , Ar supply step is followed by the Ta [N (CH ₃ ) ₂ ] The NH ₃ gas (which is an example of the second gas) for reducing Ta [N (CH ₃ ) ₂ ] ₅ is supplied to the substrate 10 on which saturated adsorption of ₅ is performed. The NH ₃ gas is supplied to the substrate 10 so that the substrate 10 is irradiated from above the substrate 10. By irradiating the substrate 10 with the NH ₃ gas, the NH ₃ is reduced in Ta [N (CH ₃ ) ₂ ] ₅ that is saturated and adsorbed on the surface of the substrate 10 and the inner surface side (inner wall) of the opening 50, An amorphous TaN film 20 is formed on the surface of the substrate 10 and the inner surface side (inner wall) of the opening 50.

In FIG. 2D, the Ar gas is supplied to the substrate 10 as an Ar supply step. The Ar gas is supplied to the base 10 so that the base 10 is irradiated from above the base 10. By irradiating the base 10 with the Ar gas, the atmosphere around the surface of the base 10 and the opening 50 is replaced. By substitution, more NH ₃ than necessary can be removed.
As described above, the ALD method of supplying the NH ₃ gas for reducing the Ta [N (CH ₃ ) ₂ ] ₅ to the substrate 10 after the Ta [N (CH ₃ ) ₂ ] ₅ , Ar supplying step. Therefore, a thin film of TaN at the atomic layer level is formed on the substrate 10, particularly on the surface of the insulating film 15 (particularly, the surface of the porous insulating film 12) with good film properties (for example, 90% or more), and It becomes possible to form uniformly.

  The TaN film 20 having a film thickness of 1 to 5 nm can be formed by repeating such FIG. 2A to FIG. 2D at least once.

FIG. 3 is a process sectional view showing a process performed corresponding to the flowchart of FIG.
In FIG. 3, a Ta [N (CH ₃ ) ₂ ] ₅ , Ar supply process is performed as a second barrier metal thin film forming process for forming the Ta film (which is an example of the second barrier metal thin film) in FIG. The process from (S110) to the Ar supply process (S116) is shown. The second barrier metal thin film forming step is performed using atomic layer vapor deposition, as in the first barrier metal thin film forming step.

In FIG. 3E, as a Ta [N (CH ₃ ) ₂ ] ₅ , Ar supply process (which is an example of a third gas supply process), the Ta [N (CH ₃ ) ₂ ] ₅ and Ar mixed gas (an example of a third gas) is supplied. The mixed gas of Ta [N (CH ₃ ) ₂ ] ₅ and Ar is supplied to the substrate 10 so that the substrate 10 is irradiated from above the substrate 10. Said _{Ta [N (CH 3) 2} ] that a gas mixture of ₅ and Ar are irradiated to the substrate 10, Ta on the substrate 10 surface and the inner surface of the opening portion 50 (the inner _{wall) [N (CH 3) 2} ] ₅ is adsorbed. Adsorption is saturated adsorption.

In FIG. 3F, the Ar gas is supplied to the substrate 10 as an Ar supply step. The Ar gas is supplied to the base 10 so that the base 10 is irradiated from above the base 10. By irradiating the base 10 with the Ar gas, the atmosphere around the surface of the base 10 and the opening 50 is replaced. By substitution, Ta [N (CH ₃ ) ₂ ] ₅ more than necessary can be removed.

In FIG. 3G, as the He / H ₂ supply step (an example of the fourth gas supply step), after the Ta [N (CH ₃ ) ₂ ] ₅ , Ar supply step, the Ta [N (CH ₃ ) The mixed gas of He / H ₂ (which is an example of the fourth gas) that reduces Ta [N (CH ₃ ) ₂ ] ₅ is supplied to the substrate 10 on which ₂ ] ₅ is saturated and adsorbed. The He / H ₂ gas is supplied to the base 10 so that the base 10 is irradiated from above the base 10. Here, the substrate 10 is exposed to a plasma atmosphere of He / H ₂ gas. By exposing the substrate 10 to a plasma atmosphere of the He / _{H 2} gas, the radical of the He / _{H 2} gas is irradiated to the substrate 10 from the top of the substrate 10. By irradiating the base 10 with radicals of the He / H ₂ gas, Ta [N (CH ₃ ) ₂ ] _{5 in} which the H ₂ radicals are saturated and adsorbed on the surface of the base 10 and the inner surface side (inner wall) of the opening 50. To form a polycrystalline Ta film 25 on the surface of the substrate 10 and the inner surface side (inner wall) of the opening 50. By using plasma, the gas of Ta [N (CH ₃ ) ₂ ] ₅ , which has been difficult in the conventional ALD method, is reduced by the radicals of He / H ₂ gas to obtain a film from which the nitriding component and the carbonizing component are removed. be able to.

In FIG. 3H, the Ar gas is supplied to the substrate 10 as an Ar supply step. The Ar gas is supplied to the base 10 so that the base 10 is irradiated from above the base 10. By irradiating the base 10 with the Ar gas, the atmosphere around the surface of the base 10 and the opening 50 is replaced. Excessive He and H ₂ can be removed by substitution.

FIG. 4 is a conceptual diagram of an apparatus for forming a barrier metal film by the ALD method.
In FIG. 4, in the apparatus 350, the base body 10 is placed on the substrate holder controlled to a predetermined temperature that also serves as the lower electrode 310 inside the chamber 300. Then, gas is supplied into the chamber 300 from the upper electrode 320. Further, the vacuum pump 330 is evacuated so that the inside of the chamber 300 has a predetermined film forming pressure. In the He / H ₂ supply process, plasma is generated between the upper electrode 320 and the lower electrode 310 inside the chamber 300 using a high frequency power source. Then, the polycrystalline Ta film 25 is formed on the inner surface of the opening 50 and the upper surface of the substrate 10 by exposing the substrate 10 to a gas plasma atmosphere and performing atomic layer vapor phase growth. In the gas supply process by the ALD method other than the He / H ₂ supply process, each gas is supplied without generating plasma.

As described _{above, Ta [N (CH 3)} 2] after ₅ supply, said _{Ta [N (CH 3) 2} ] 5 reduction of the supply to the substrate 10 using ALD the He / _{H 2} Since it is carried out particularly by hydrogen radicals formed in a gas plasma atmosphere, it becomes possible to form an atomic layer level Ta thin film on the substrate 10 with good coating properties (for example, 90% or more) and uniformly.

  The Ta film 25 having a film thickness of 1 to 5 nm can be formed by repeating such FIG. 3 (e) to FIG. 3 (h) at least once.

FIG. 5 is a diagram illustrating an example of a method of supplying a mixed gas of Ta [N (CH ₃ ) ₂ ] ₅ and Ar in the Ta [N (CH ₃ ) ₂ ] ₅ , Ar supply step (S102, S110). is there.
In FIG. 5, solid Ta [N (CH ₃ ) ₂ ] ₅ contained in a container is heated to 50 to 90 ° C. and warmed. Warmed melted _{Ta [N (CH 3) 2} ] By supplying Ar gas into _5, and supplies to the chamber 300 by the gasified _{Ta [N (CH 3) 2} ] ₅ the kind of bubbling with Ar be able to.

FIG. 6 is a diagram showing a supply flow of each gas in the TaN film formation step.
As described above, TaN having a desired film thickness can be obtained by repeating each step (S102 to S108) as one cycle.

The conditions of the TaN film forming process in the present embodiment are as follows as an example.
First, the substrate 10 placed on the substrate holder is controlled to 250 to 300 ° C. as a predetermined temperature. Further, the film forming pressure in the chamber 300 when each gas is supplied in each step (S102 to S108) is set to 133 Pa (1 Torr) or more and 1333 Pa (10 Torr) by the vacuum pump 330.

In the Ta [N (CH ₃ ) ₂ ] ₅ , Ar supply step (S102), the flow rate of Ar is 0.17 Pa · m ³ / s as a mixed gas of Ta [N (CH ₃ ) ₂ ] ₅ and Ar. (100 sccm) to 1.7 Pa · m ³ / s (1000 sccm) is supplied for 0.25 s to 2 s. Further, Ta [N (CH ₃ ) ₂ ] ₅ gasified together with the supplied Ar is supplied to the chamber 300.

Then, in the Ar supply step (S104, S108), the flow rate of Ar as ^{0.84Pa · m 3 /s(500sccm)~5.1Pa · m 3} / s (3000sccm), supplied between 0.25s~2s To do. By making the flow rate of Ar more than Ta [N (CH ₃ ) ₂ ] ₅ , the substrate surface can be sufficiently replaced. By sufficiently replacing the substrate surface, impurities in the TaN film formed can be reduced.

NH ₃ in the supplying step (S106), the flow rate of NH ₃ as ^{0.84Pa · m 3 /s(500sccm)~5.1Pa · m 3} / s (3000sccm), supplied between 0.25S～2s. By making the flow rate of NH ₃ higher than Ta [N (CH ₃ ) ₂ ] ₅ , the reduction action can be promoted and impurities in the formed TaN film can be reduced.

  By repeating each of the steps (S102 to S108) as 20 cycles to 100 cycles, a TaN film having a thickness of 1 to 5 nm can be obtained.

FIG. 7 is a conceptual diagram for explaining how a TaN film is formed in the ALD method.
In FIG. 7A, TaR20 (Ta compound) is adsorbed on the substrate 10 by supplying TaR20 (Ta compound) (Ta [N (CH ₃ ) ₂ ] _{5 in} this embodiment). Further, TaR 20 that is not adsorbed floats around the substrate 10.
In FIG. 7B, the floating TaR 20 is replaced by supplying Ar.
In FIG. 7C, by supplying NH ₃ , TaR 20 adsorbed on the substrate 10 is reduced to form a TaN film 22.

FIG. 8 is a diagram showing a supply flow of each gas in the Ta film forming step.
As described above, a Ta film having a desired thickness can be obtained by repeating each step (S110 to S116) as one cycle.

The conditions of the TaN film forming process in the present embodiment are as follows as an example.
First, the substrate 10 placed on the substrate holder is controlled to 250 to 300 ° C. as a predetermined temperature. Further, in each step of Ta [N (CH ₃ ) ₂ ] ₅ , Ar supply step (S110) and Ar supply step (S112, S116), the film forming pressure in the chamber 300 when each gas is supplied. Is set to 133 Pa (1 Torr) or more and 1333 Pa (10 Torr) by the vacuum pump 330.

In the Ta [N (CH ₃ ) ₂ ] ₅ , Ar supply step (S110), the flow rate of Ar is 0.17 Pa · m ³ / s as a mixed gas of Ta [N (CH ₃ ) ₂ ] ₅ and Ar. (100 sccm) to 1.7 Pa · m ³ / s (1000 sccm) is supplied for 0.25 s to 2 s. Similarly to the formation of the TaN film, by supplying Ar gas into the heated and melted Ta [N (CH ₃ ) ₂ ] ₅ , gasified Ta [N (CH ₃ ) ₂ together with the supplied Ar. ] ₅ is supplied to the chamber 300.

Then, in the Ar supply step (S112, S116), the flow rate of Ar as ^{0.84Pa · m 3 /s(500sccm)~5.1Pa · m 3} / s (3000sccm), supplied between 0.25s~2s To do. By making the flow rate of Ar more than Ta [N (CH ₃ ) ₂ ] ₅ , the substrate surface can be sufficiently replaced. By sufficiently replacing the substrate surface, impurities in the TaN film formed can be reduced.

In the He / H ₂ supply step (S114), the flow rate of the mixed gas in which He is 2 to 10% and H ₂ is 90 to 98% is 0.084 Pa · m ³ / s (50 sccm) to 0.84 Pa · m ^3. / S (500 sccm) is supplied for 0.25 s to 2 s. The film forming pressure in the chamber 300 when the gas is supplied is set to 0.13 Pa (10 mTorr) or more and 1.3 Pa (100 mTorr) by the vacuum pump 330. The plasma power is set to 300 to 3000 W. By flowing a He-containing mixed gas, plasma is generated, and Ta [N (CH ₃ ) ₂ ] ₅ can be reduced by H ₂ radicals that become radicals by the plasma and have a strong reducing action.

  By repeating each step (S110 to S116) as one cycle, a Ta film having a thickness of 1 to 5 nm can be obtained.

FIG. 9 is a conceptual diagram for explaining how a Ta film is formed in the ALD method.
In FIG. 9A, TaR20 (Ta compound) is adsorbed on the substrate 10 by supplying TaR20 (Ta compound) (in this embodiment, Ta [N (CH ₃ ) ₂ ] ₅ ). Further, TaR 20 that is not adsorbed floats around the substrate 10.
In FIG. 9B, the floating TaR 20 is replaced by supplying Ar.
In FIG. 9C, the Ta film 20 is formed by reducing the TaR 20 adsorbed on the substrate 10 by supplying a He / H ₂ mixed gas.

Accordingly, an ultra-thin laminated film having a thickness of 10 nm or less in which the Ta film 25 having a different composition is formed on the TaN film 20 in FIG. 3 can be uniformly formed on the substrate with good film properties by the above process. In other words, on the TaN film _{20, Ta [N (CH 3} ) 2] wherein the ₅ gas _{Ta [N (CH 3) 2} ] Ta film using the the He / _{H 2} gas for reducing the ₅ gas By forming 25, the composition in the film thickness direction of the barrier metal can be controlled to form a multilayer film. Then, by forming a Ta film 25 which is an example of a metal film having a nitrogen concentration lower than that of the TaN film 20 on the TaN film 20, the nitrogen concentration can be reduced with respect to a conductive material formed later. The high TaN film 20 can improve the diffusion preventing property, and the Ta film 25 can improve the adhesion. Here, it is desirable that the TaN film 20 forming step and the Ta film 25 forming step be performed continuously. Oxidation can be prevented by exposure to the atmosphere. In order to carry out continuously, it is desirable to perform the formation process of TaN film | membrane 20 and the formation process of Ta film | membrane 25 continuously, without taking out the base | substrate 10 from the chamber 300. FIG. By not removing the substrate 10 from the chamber 300, exposure to the atmosphere can be avoided.

  The inventors have also found that 1 nm or more is desirable in order to prevent diffusion of Cu in the TaN film 20. In addition, in order to improve the adhesion of Cu with the Ta film 25, it has been found that 2 to 5 nm or more is desirable. Therefore, in the present embodiment, the Ta film 25 is formed to have a thickness of 1 to 5 nm, but it is more preferable to form the Ta film 25 to 2 to 5 nm. Therefore, in order to make the entire barrier metal film as thin as possible by setting the minimum film thickness, the film thickness of the Ta film 25 is set so that the ratio of the Ta film 25 and the TaN film 20 is 2 to 5 times. It is more desirable to form a film having a thickness greater than 20. However, the present invention is not limited to this, and other ratios may be used as long as the TaN film 20 is formed with a film thickness capable of preventing Cu diffusion. For example, the thickness of the Ta film 25 may be 1 to 2 times the thickness of the TaN film 20 having a thickness of 2 nm. However, it is desirable to form the barrier metal film as thin as possible.

FIG. 10 is a process cross-sectional view illustrating a main part of a process performed after the process performed corresponding to the flowchart of FIG. 1.
FIG. 10 shows from the seed layer formation step to the planarization step following the Ar supply step shown in FIG.

  In FIG. 10 (i), as a seed layer forming step as a part of the conductive material deposition step, Cu serving as a cathode electrode in the next electrolytic plating step is performed by physical vapor deposition (PVD) method such as sputtering. A thin film is deposited (formed) on the inner wall of the opening 50 where the Ta film 25 as a barrier metal film is formed and the surface of the substrate 10 as a seed layer 30.

  In FIG. 10 (j), as a plating process as a part of the conductive material deposition process, a conductive film is formed by electro chemical deposition (ECD method) such as electrolytic plating using a Cu thin film as a seed layer as a cathode electrode. Cu 35 serving as a conductive portion made of a conductive material is deposited on the opening 50 and the surface of the substrate 10.

In FIG. 10 (k), as a planarization step, Cu 35 and seed layer 30 serving as a wiring layer as a conductive portion deposited on the surface of the SiO ₂ insulating film 13 by the CMP method, and Ta serving as a barrier metal layer therebelow. By polishing and removing the film 25 and the TaN film 20, a buried structure as shown in FIG. 5K is formed.

  As described above, the semiconductor device according to the present embodiment includes the insulating film 15 serving as the insulating layer using the insulating material disposed on the base 10 and the conductive material Cu disposed in the insulating layer. The first and second Cu35 and seed layer 30 that are used as the conductive parts, and the first and second layers are arranged between the seed layer 30 and the insulating material and have a minimum dimension of less than 10 nm. A Ta film 25 and a TaN film 20 are provided as barrier metal thin film portions. Then, by providing the Ta film 25 and the TaN film 20 and forming a multilayer film having adhesion and diffusion prevention, a semiconductor device provided with a barrier metal having adhesion and diffusion prevention can be obtained. Moreover, since the minimum dimension of each film thickness of the Ta film 25 and the TaN film 20 is smaller than 10 nm, the wiring resistance and the via resistance can be reduced as compared with the conventional case.

In the present embodiment, He / H ₂ plasma is used to form the Ta film 25, but the present invention is not limited to this. For example, Ar / H ₂ plasma, neon (Ne) / H ₂ plasma, krypton (Kr) ) / H ₂ plasma, xenon (Xe / H ₂ plasma), radon (Rn) / H ₂ plasma, and other plasmas using other inert gases can be expected to have the same effect. However, if the element used for the inert gas is heavy, the element may be implanted into the Ta film 25, so that the element used for the inert gas is preferably a lighter element such as He.

  In the present embodiment, the TaN film 20 is exemplified as the metal nitride film for improving the diffusion preventing property. However, the present invention is not limited to this. For example, the WN film, TiN film, ZrN (zirconium nitride) film, MoN ( Similar effects can be obtained with other refractory metal nitride films such as molybdenum nitride) film, TaCN film, WCN film, ZrCN (zirconium carbonitride) film, and MoCN (molybdenum carbonitride) film. Further, the Ta film 25 has been described as the metal film for improving the adhesion, but the present invention is not limited thereto. For example, a W (tungsten) film, a Ti (titanium) film, a Zr (zirconium) film, and a Mo (molybdenum) film. Similar effects can be obtained with other high melting point metal films.

  Further, the same effect may be obtained even if the metal of the metal nitride film is different from the metal of the metal film.

  As described above, in the present embodiment, a nitride of the first metal is used by using the ALD method and the compound containing the first metal and the compound that has a reducing property to the compound and contains nitrogen. A thin film of (a high melting point metal nitrogen compound having excellent anti-diffusion properties for Cu but poor adhesion), and a compound containing a second metal on the first metal nitride thin film; By using a plasma having reducibility with respect to the compound, a laminated film structure that forms a thin film of a single element of a second metal (here, a single element of a refractory metal that supplements poor adhesion), A laminated structure thin film in which the composition ratio of the metal element and nitrogen is controlled is formed.

Embodiment 2. FIG.
FIG. 11 is a flowchart showing a main part of the method of manufacturing a semiconductor device in the second embodiment. FIG. 11 shows a process for forming a barrier metal, in particular, as in the first embodiment.
In FIG. 11, in the present embodiment, Ta [N (CH ₃ ) ₂ that supplies Ta [N (CH ₃ ) ₂ ] ₅ and Ar to form a TaN film as a first barrier metal film. ] _5, Ar supplying step (S102), Ar supply step of supplying a Ar (S104), NH supplies NH _{3 3} supply step (S106), 1 a series of steps that Ar supply step of supplying a Ar (S108) Carry out multiple rounds of two or more rounds. That is, the series of steps is performed at least once.

Then, Ta [N (CH ₃ ) ₂ ] that supplies Ta [N (CH ₃ ) ₂ ] ₅ and Ar to form a TaNx film (where x <1) is used as the second barrier metal film. ₅ , Ar supply step (S110), Ar supply step (S112) for supplying Ar, N ₂ / H ₂ supply step (S214) for supplying N ₂ (nitrogen) and H ₂ (hydrogen), Ar is supplied A series of steps called Ar supply step (S116) is carried out a plurality of times, one round or two rounds. That is, the series of steps is performed at least once. FIG. 11 is the same as FIG. 1 except that the He / H ₂ supply step (S114) in FIG. 1 of the first embodiment is replaced with an N ₂ / H ₂ supply step (S214).

FIG. 12 is a process sectional view showing a process performed corresponding to the flowchart of FIG.
Here, a Ta [N (CH ₃ ) ₂ ] ₅ , Ar supply step (first barrier metal thin film forming step for forming the TaN film (an example of the first barrier metal thin film) in FIG. 11 ( The steps from S102) to Ar supply step (S108) are the same as those in FIG.
In FIG. 12, as a second barrier metal thin film formation step for forming the TaNx film (where x <1) (which is an example of the second barrier metal thin film) in FIG. 11, Ta [N (CH ₃ ) ₂ ] ₅ , Ar supply process (S110) to Ar supply process (S116). The second barrier metal thin film forming step is performed using atomic layer vapor deposition, as in the first barrier metal thin film forming step.
Also, FIG. 12E and FIG. 12F are the same as FIG. 3E and FIG.

In FIG. 12 _(g), N a 2 / _{H 2} supply process (fourth, which is an example of a gas supply _{step), Ta [N (CH 3} ) 2] after ₅ supply, said Ta [N _{(CH 3) 2} ] The mixed gas of N ₂ / H ₂ (which is an example of the fourth gas) for reducing Ta [N (CH ₃ ) ₂ ] ₅ is supplied to the substrate 10 on which ₅ is saturated and adsorbed. The supply of the N ₂ / H ₂ gas to the substrate 10 is performed such that the substrate 10 is irradiated from above the substrate 10. Here, the substrate 10 is exposed to a plasma atmosphere of N ₂ / H ₂ gas. N ₂ / _{H 2} by exposing the substrate 10 to a plasma atmosphere of the _gas, a radical of the N 2 / _{H 2} gas is irradiated to the substrate 10 from the top of the substrate 10. When the substrate 10 is irradiated with radicals of the N ₂ / H ₂ gas, N ₂ / H ₂ is adsorbed on the surface of the substrate 10 and the inner surface side (inner wall) of the opening 50. Adsorption is saturated adsorption. Then, the saturated adsorbed N ₂ radical and H ₂ radical reduce Ta [N (CH ₃ ) ₂ ] ₅ saturated and adsorbed on the surface of the substrate 10 and the inner surface side (inner wall) of the opening 50, thereby reducing the substrate 10. A polycrystalline TaNx film 125 (x <1) is formed on the surface and the inner surface side (inner wall) of the opening 50.

In FIG. 12H, the Ar gas is supplied to the substrate 10 as an Ar supply step. The Ar gas is supplied to the base 10 so that the base 10 is irradiated from above the base 10. By irradiating the base 10 with the Ar gas, the atmosphere around the surface of the base 10 and the opening 50 is replaced. By substitution, more N ₂ and H ₂ than necessary can be removed.

As described _{above, Ta [N (CH 3)} 2] after ₅ supply, said _{Ta [N (CH 3) 2} ] 5 reduced in the plasma atmosphere of the _N 2 / _{H 2} gas supplied to the substrate 10 Since the ALD method is performed using the formed nitrogen radicals and hydrogen radicals, a thin film of TaNx (provided that x <1) at the atomic layer level where the ratio of nitrogen to Ta is 1 or less is coated on the substrate 10. Good (for example, 90% or more) can be formed uniformly. Here, in the case of the ALD method that does not use plasma, when the TaN film 20 in the first embodiment and the second embodiment is formed, only the nitriding occurs because the reduction is performed only with NH ₃ . However, in the ALD method using plasma, when the reduction is performed by two types of radicals of a nitrogen radical and a hydrogen radical as in the second embodiment, nitridation by nitrogen radical and reduction by hydrogen radical in the first embodiment is performed. Since other reactions also occur, the amount of nitrogen mixed can be reduced compared to the ALD method that does not use plasma. The concentration of nitrogen can be controlled to an arbitrary value by controlling the nitrogen partial pressure, plasma power, nitrogen supply flow rate, and the like. That is, it is possible to form a thin film in which the composition ratio between the metal element and nitrogen, which has been difficult in the conventional ALD method, is controlled.

As an example, the conditions of the Ta film forming step in the present embodiment are as follows. The steps other than the N ₂ / H ₂ supply step (S214) are the same as those in the first embodiment, and will be omitted.

In the N ₂ / H ₂ supply step (S214), the flow rate of the mixed gas in which N ₂ is 20 to 50% and H ₂ is 50 to 80% is set to 0.084 Pa · m ³ / s (50 sccm) to 0.84 Pa ·. as m ³ / s (500sccm), supplied between 0.25S～2s. The film forming pressure in the chamber 300 when the gas is supplied is set to 0.13 Pa (10 mTorr) or more and 1.3 Pa (100 mTorr) by the vacuum pump 330. The plasma power is set to 300 to 3000 W. Plasma is generated by flowing a mixed gas containing He, and Ta [N (CH ₃ ) ₂ ] ₅ can be reduced by the N ₂ radical and the H ₂ radical that are converted into radicals by the plasma and have a strong reducing action.

By repeating each step (S110 to S116) in FIG. 11 as one cycle, a TaNx film 125 (where x <1) having a film thickness of 1 to 5 nm can be formed.
Therefore, an ultra-thin laminated film of 10 nm or less in which a TaNx film 125 (where x <1) having a different composition is formed on the TaN film 20 by the above-described process is uniformly formed on the substrate with good film properties. be able to. In other words, TaNx is used on the TaN film 20 by using Ta [N (CH ₃ ) ₂ ] ₅ gas and N ₂ / H ₂ gas for reducing the Ta [N (CH ₃ ) ₂ ] ₅ gas. By forming the film 125 (x <1), the composition in the film thickness direction of the barrier metal can be controlled to form a multilayer film. Then, a TaNx film 125 (however, x <1), which is an example of a metal film having a nitrogen concentration lower than that of the TaN film 20, is formed on the TaN film 20, thereby forming a conductive material that will be formed later. With respect to the material, the TaN film 20 having a high nitrogen concentration can improve the diffusion preventing property, and the TaNx film 125 (where x <1) can improve the adhesion.

FIG. 13 is a process cross-sectional view illustrating a main part of a process performed after the process performed corresponding to the flowchart of FIG. 11.
FIG. 13 shows from the seed layer formation step to the planarization step following the Ar supply step shown in FIG.

  In FIG. 13 (i), as a seed layer forming step as a part of the conductive material deposition step, Cu serving as a cathode electrode in the next electrolytic plating step is performed by physical vapor deposition (PVD) method such as sputtering. A thin film is deposited (formed) on the inner wall of the opening 50 where the TaNx film 125 (x <1) as a barrier metal film and the surface of the substrate 10 are formed as a seed layer 30.

  In FIG. 13 (j), as a plating process as a part of the conductive material deposition process, a Cu thin film as a seed layer is used as a cathode electrode, and a conductive part made of a conductive material by electro-vapor deposition such as electrolytic plating. Cu 35 is deposited on the opening 50 and the surface of the substrate 10.

In FIG. 13 (k), as a planarization step, Cu 35 and seed layer 30 serving as a wiring layer as a conductive portion deposited on the surface of the SiO ₂ insulating film 13 by the CMP method, and TaNx serving as a barrier metal layer therebelow. By polishing and removing the film 125 (x <1) and the TaN film 20, a buried structure as shown in FIG. 13K is formed.

  As described above, the semiconductor device according to the present embodiment includes the insulating film 15 serving as the insulating layer using the insulating material disposed on the base 10 and the conductive material Cu disposed in the insulating layer. The first and second Cu35 and seed layer 30 that are used as the conductive parts, and the first and second layers are arranged between the seed layer 30 and the insulating material and have a minimum dimension of less than 10 nm. A TaNx film 125 (x <1) and a TaN film 20 to be a barrier metal thin film portion were provided. A semiconductor device provided with a barrier metal having adhesion and diffusion prevention properties by providing a TaNx film 125 (x <1) and TaN film 20 and having a multilayer film having adhesion and diffusion prevention properties. Can be obtained. Further, since the minimum dimension of each film thickness of the TaNx film 125 (x <1) and the TaN film 20 is smaller than 10 nm, the wiring resistance and via resistance can be reduced as compared with the conventional case.

Embodiment 3 FIG.
In each of the above embodiments, the film is formed by the parallel plate type apparatus 350 shown in FIG. 4, but the present invention is not limited to this, and other plasma film forming apparatuses may be used.
FIG. 14 is a conceptual diagram of a remote plasma apparatus.
In the apparatus 350 shown in FIG. 4, plasma is generated at a position close to the surface of the substrate 10, but when plasma is generated at a position close to the surface of the substrate 10, radicals strongly collide with the surface of the substrate 10 and damage the substrate 10. There is also a risk of giving. On the other hand, in the apparatus 450 shown in FIG. 14, plasma is generated at a position far from the surface of the substrate 10 disposed on the substrate holder 410 and before the gas is supplied to the chamber 400, and thus the damage caused by radicals on the substrate 10. Can be reduced.

  As described above, the TaN film 20 and the Ta film 25 or the TaNx film 125 (where x <1) are formed on the insulating film that needs to be prevented from diffusing into the pores, which is a porous insulating material. If the adhesion and diffusion prevention of Cu can be improved with the film 20 and the Ta film 25 or the TaNx film 125 (x <1), a low dielectric constant porous insulating material can be used for the insulating film. become. Since a porous dielectric material having a low dielectric constant can be used for the insulating film, the capacitance between wirings can be reduced. Since the inter-wiring capacitance can be reduced, the delay constant in the wiring can be reduced. Therefore, the device operation can be speeded up.

  Here, as a material for the wiring layer in each of the above embodiments, a material mainly composed of Cu used in the semiconductor industry, such as a Cu—Sn alloy, a Cu—Ti alloy, a Cu—Al alloy, etc., is used in addition to Cu35. The same effect can be obtained. Furthermore, the same effect can be obtained by using other metal materials used in the semiconductor industry whose main components are aluminum (Al), tungsten (W), etc., instead of Cu-based materials.

  In the case of forming a multilayer wiring structure or the like, the substrate 10 in FIG. 2, FIG. 3, FIG. 5, FIG. 7, and FIG. 8 is one in which a lower wiring layer and an insulating film are formed.

  In the above embodiment, a method of forming a Cu wiring in a wiring groove or a via hole by a damascene method has been described. However, Cu serving as a wiring material is deposited (embedded) in the wiring groove and a via hole under the wiring groove at a time. Similar effects can be obtained in the dual damascene method.

In each of the above embodiments, the material of the porous insulating film 12 is not limited to the MSQ as the porous dielectric thin film material, and other porous inorganic insulating film materials and porous organic insulating film materials are used. However, the same effect can be obtained.
In particular, when the above-described embodiments are applied to a porous low dielectric constant material, a remarkable effect can be obtained as described above. Examples of materials that can be used as the material of the porous insulating film 12 in each of the above-described embodiments include various silsesquioxane compounds, polyimide, fluorocarbon, parylene, and benzocyclobutene. And various insulating materials.

  The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples.

  For example, the substrate 10 on which the interlayer insulating film is formed in each embodiment can have various semiconductor elements or structures not shown. Further, an interlayer insulating film may be further formed on a wiring structure having an interlayer insulating film and a wiring layer instead of the semiconductor substrate. The opening may be formed so that the semiconductor substrate is exposed, or may be formed on the wiring structure.

  Furthermore, as for the film thickness of the interlayer insulating film and the size, shape, number, and the like of the opening 50, those required in the semiconductor integrated circuit and various semiconductor elements can be appropriately selected and used.

  In addition, any semiconductor device manufacturing method that includes the elements of the present invention and whose design can be changed as appropriate by those skilled in the art is included in the scope of the present invention.

  In addition, for the sake of simplicity of explanation, techniques usually used in the semiconductor industry, such as a photolithography process, cleaning before and after processing, are omitted, but it goes without saying that these techniques are included.

3 is a flowchart showing a main part of a method for manufacturing a semiconductor device in the first embodiment. It is process sectional drawing showing the process implemented corresponding to the flowchart of FIG. It is process sectional drawing showing the process implemented corresponding to the flowchart of FIG. It is a conceptual diagram of the apparatus which performs the barrier metal film formation by ALD method. _{Ta [N (CH 3) 2} ] 5, a diagram illustrating an example of a method for supplying a mixed gas of the Ar supply by step _{(S102, S110) Ta [N} (CH 3) 2] 5 and Ar. It is a figure which shows the supply flow of each gas in a TaN film formation process. It is a conceptual diagram for demonstrating a TaN film | membrane being formed in ALD method. It is a figure which shows the supply flow of each gas in Ta film formation process. It is a conceptual diagram for demonstrating a Ta film | membrane being formed in ALD method. It is process sectional drawing showing the principal part of the process implemented after the process implemented corresponding to the flowchart of FIG. 10 is a flowchart showing a main part of a method for manufacturing a semiconductor device in a second embodiment. It is process sectional drawing showing the process implemented corresponding to the flowchart of FIG. It is process sectional drawing showing the principal part of the process implemented after the process implemented corresponding to the flowchart of FIG. It is a conceptual diagram of a remote plasma apparatus. It is process sectional drawing showing the principal part of a damascene method.

Explanation of symbols

10 base 11 SiC insulating film 12 porous dielectric film 13 SiO ₂ insulating film 15 insulating film 20, 22 TaN film 25, 32 Ta film 30 seed layer 35 Cu
50 Opening 125 TaNx film 200 Base body 220 Interlayer insulating film 240 Barrier metal layer 260 Cu layer 300 Chamber 310 Lower electrode 320 Upper electrode 330 Vacuum pump 350 Device 400 Chamber 410 Substrate holder 450 Device

Claims (7)

A first barrier metal thin film forming step of forming a first barrier metal thin film on a substrate using a first gas and a second gas for reducing the first gas;
A fourth gas that reduces the third gas and the third gas on the first barrier metal thin film formed by the first barrier metal thin film forming step without exposing the substrate to the atmosphere. A second barrier metal thin film forming step of forming a second barrier metal thin film using
A method for manufacturing a semiconductor device, comprising: The first barrier metal thin film forming step includes:
A first gas supply step of supplying the first gas to the substrate;
A second gas supply step for supplying the second gas to the substrate after the first gas supply step;
In the first barrier metal thin film forming step, by repeating the first gas supply step and the second gas supply step, a first barrier metal thin film having a predetermined thickness is formed,
The second barrier metal thin film forming step includes
A third gas supply step for supplying the third gas to the substrate after the second gas supply step;
A fourth gas supply step for supplying the fourth gas to the substrate after the third gas supply step;
Have
In the second barrier metal thin film forming step, by repeating the third gas supply step and the fourth gas supply step, the first barrier metal thin film having a thickness larger than that of the first barrier metal thin film having the predetermined thickness is obtained. 2. The method of manufacturing a semiconductor device according to claim 1, wherein two barrier metal thin films are formed. In the first barrier metal thin film formation step, the first barrier metal thin film is formed using atomic layer vapor deposition.
2. The method of manufacturing a semiconductor device according to claim 1, wherein the second barrier metal thin film is formed by atomic layer vapor deposition in the second barrier metal thin film forming step.   3. The method of manufacturing a semiconductor device according to claim 2, wherein in the second barrier metal thin film forming step, the substrate is exposed to a plasma atmosphere of the fourth gas supplied by the fourth gas supply step. The base is provided with an insulating film using a porous insulating material,
5. The method of manufacturing a semiconductor device according to claim 1, wherein in the first barrier metal thin film forming step, the first barrier metal thin film is formed on a surface of the insulating film. . In the first barrier metal thin film forming step, a metal nitride film is formed as the first barrier metal thin film,
6. The metal film having a nitrogen concentration lower than that of the first barrier metal thin film is formed as the second barrier metal thin film in the second barrier metal thin film forming step. A method for manufacturing a semiconductor device according to claim 1. An insulating layer using an insulating material disposed on the substrate;
A wiring portion using a wiring material disposed in the insulating layer;
First and second barrier metal thin film portions disposed between the wiring portion and the insulating material and having a minimum dimension of each film thickness smaller than 10 nm;
A semiconductor device comprising:

Images