Barrier metal film production method

A Cl2 gas plasma is generated at a site within a chamber between a substrate and a metal member. The metal member is etched with the Cl2 gas plasma to form a precursor. A nitrogen gas is excited in a manner isolated from the chamber accommodating the substrate. A metal nitride is formed upon reaction between excited nitrogen and the precursor, and formed as a film on the substrate. After film formation of the metal nitride, a metal component of the precursor is formed as a film on the metal nitride on the substrate. In this manner, a barrier metal film with excellent burial properties and a very small thickness is produced at a high speed, with diffusion of metal being suppressed and adhesion to the metal being improved.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a production method for a barrier metal film to be formed on the surface of a substrate for eliminating the diffusion of a metal into the substrate, when a metal film is formed on the surface of the substrate.

2. Description of Related Art

Semiconductors with electrical wiring have increasingly used copper as a material for the wiring in order to increase the speed of switching, decrease transmission loss, and achieve a high density. In applying the copper wiring, it has been common practice to perform the vapor phase growth method or plating on a substrate having a depression for wiring on its surface, thereby forming a copper film on the surface including the depression.

In forming the copper film on the surface of the substrate, a barrier metal film (for example, a nitride of tantalum, tungsten, titanium or silicon) is prepared beforehand on the surface of the substrate in order to eliminate the diffusion of copper into the substrate, and retain the adhesion of copper. When plating is employed, a copper shielding layer is formed on the barrier metal film by physical or chemical vapor deposition, and used also as an electrode. The barrier metal film has been formed by physical vapor deposition such as sputtering.

The depression for wiring, formed on the surface of the substrate, tends to be decreased in size, and a demand is expressed for a further reduction in the thickness of the barrier metal film. However, the barrier metal film has been produced by use of sputtering, and its directionality is not uniform. With a tiny depression on the surface of the substrate, therefore, the film is formed at the entrance of the depression before being formed in the interior of the depression, resulting in insufficient burial of the depression. Also, the substrate has been badly damaged.

SUMMARY OF THE INVENTION

The present invention has been accomplished in light of the circumstances described above. An object of the invention is to provide a barrier metal film production apparatus and a barrier metal film production method which can form a barrier metal film with excellent burial properties and a very small thickness at a high speed.

According to the present invention, there is provided a barrier metal film production apparatus, comprising:

a chamber accommodating a substrate;

a metallic etched member provided in the chamber at a position opposed to the substrate;

source gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

excitation means for exciting a nitrogen gas in a manner isolated from the chamber;

formation means for forming a metal nitride upon reaction between nitrogen excited by the excitation means and the precursor; and

control means which makes a temperature of the substrate lower than a temperature of the formation means to form the metal nitride by the reduction reaction as a film on the substrate.

Thus, a barrier metal film comprising a film of a metal nitride and suppressing diffusion can be prepared by forming a metal with the use of a plasma. The barrier metal film can be formed uniformly to a small thickness. Consequently, the barrier metal film can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

According to the present invention, there is also provided a barrier metal film production apparatus, comprising:

a chamber accommodating a substrate;

a metallic etched member provided in the chamber at a position opposed to the substrate;

source gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

excitation means for exciting a nitrogen gas in a manner isolated from the chamber;

formation means for forming a metal nitride upon reaction between nitrogen excited by the excitation means and the precursor; and

control means which makes a temperature of the substrate lower than a temperature of the formation means to form the metal nitride as a film on the substrate, and after film formation of the metal nitride, stops supply of the nitrogen gas, and makes the temperature of the substrate lower than a temperature of the etched member to form the metal component of the precursor by the reduction reaction as a film on the metal nitride on the substrate.

Thus, a barrier metal film comprising a film of a metal nitride and a metal film and with diffusion suppressed and adhesion improved can be prepared by forming a metal by plasmas. The barrier metal film can be formed uniformly to a small thickness. Consequently, the barrier metal film can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

According to the present invention, there is also provided a barrier metal film production apparatus, comprising:

a chamber accommodating a substrate;

a metallic etched member provided in the chamber at a position opposed to the substrate;

source gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

nitrogen gas supply means for supplying a nitrogen gas to an interior of the chamber between the substrate and the etched member;

plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma and a nitrogen gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and that a metal nitride is formed upon reaction between nitrogen and the precursor; and

control means which makes a temperature of the substrate lower than a temperature of the etched member to form the metal nitride by the reduction reaction as a film on the substrate.

Thus, a barrier metal film comprising a film of a metal nitride and a metal film and with diffusion suppressed can be prepared by forming a metal by plasmas. The barrier metal film can be formed uniformly to a small thickness. Also, the supply lines for gases can be simplified, and the number of plasma sources can be decreased, so that the product cost can be reduced. Consequently, the barrier metal film can be formed highly accurately at a high speed and at a low cost with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

According to the present invention, there is also provided a barrier metal film production apparatus, comprising:

a chamber accommodating a substrate;

a metallic etched member provided in the chamber at a position opposed to the substrate;

source gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

nitrogen gas supply means for supplying a nitrogen gas to an interior of the chamber between the substrate and the etched member;

plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma and a nitrogen gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and that a metal nitride is formed upon reaction between nitrogen and the precursor; and

control means which makes a temperature of the substrate lower than a temperature of the etched member to form the metal nitride by the reduction reaction as a film on the substrate, then stops supply of the nitrogen gas, and makes the temperature of the substrate lower than the temperature of the etched member to form the metal component of the precursor as a film on the metal nitride on the substrate.

Thus, a barrier metal film comprising a film of a metal nitride and a metal film and with diffusion suppressed and adhesion improved can be prepared by forming a metal by plasmas. The barrier metal film can be formed uniformly to a small thickness. Also, the supply lines for gases can be simplified, and the number of plasma sources can be decreased, so that the product cost can be reduced. Consequently, the barrier metal film can be formed highly accurately at a high speed and at a low cost with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

According to the present invention, there is also provided a barrier metal film production method comprising:

supplying a source gas containing a halogen to an interior of a chamber between a substrate and a metallic etched member;

converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

exciting a nitrogen gas in a manner isolated from the chamber accommodating the substrate;

forming a metal nitride upon reaction between excited nitrogen and the precursor; and

making a temperature of the substrate lower than a temperature of means for formation of the metal nitride to form the metal nitride by the reduction reaction as a film on the substrate.

Thus, a barrier metal film comprising a film of a metal nitride and suppressing diffusion can be prepared by forming a metal by plasma. The barrier metal film can be formed uniformly to a small thickness. Consequently, the barrier metal film can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

According to the present invention, there is also provided a barrier metal film production method comprising:

supplying a source gas containing a halogen to an interior of a chamber between a substrate and a metallic etched member;

converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

exciting a nitrogen gas in a manner isolated from the chamber accommodating the substrate;

forming a metal nitride upon reaction between excited nitrogen and the precursor;

making a temperature of the substrate lower than a temperature of means for formation of the metal nitride to form the metal nitride by the reduction reaction as a film on the substrate; and

after film formation of the metal nitride, stopping supply of the nitrogen gas, and making the temperature of the substrate lower than a temperature of the etched member to form the metal component of the precursor as a film on the metal nitride on the substrate.

Thus, a barrier metal film comprising a film of a metal nitride and a metal film and with diffusion suppressed and adhesion improved can be prepared by forming a metal by plasmas. The barrier metal film can be formed uniformly to a small thickness. Consequently, the barrier metal film can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

According to the present invention, there is also provided a barrier metal film production method comprising:

supplying a source gas containing a halogen and a nitrogen gas to an interior of a chamber between a substrate and a metallic etched member;

converting an atmosphere within the chamber into a plasma to generate a source gas plasma and a nitrogen gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and that a metal nitride is formed upon reaction between nitrogen and the precursor; and

making a temperature of the substrate lower than a temperature of the etched member to form the metal nitride by the reduction reaction as a film on the substrate.

Thus, a barrier metal film comprising a film of a metal nitride and with diffusion suppressed can be prepared by forming a metal by plasmas. The barrier metal film can be formed uniformly to a small thickness. Also, the supply line for gases can be simplified, and the number of plasma sources can be decreased, so that the product cost can be reduced. Consequently, the barrier metal film can be formed highly accurately at a high speed and at a low cost with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

According to the present invention, there is also provided a barrier metal film production method comprising:

supplying a source gas containing a halogen and a nitrogen gas to an interior of a chamber between a substrate and a metallic etched member;

converting an atmosphere within the chamber into a plasma to generate a source gas plasma and a nitrogen gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and that a metal nitride is formed upon reaction between nitrogen and the precursor;

making a temperature of the substrate lower than a temperature of the etched member to form the metal nitride by the reduction reaction as a film on the substrate; and

after film formation of the metal nitride, stopping supply of the nitrogen gas, and making the temperature of the substrate lower than the temperature of the etched member to form the metal component of the precursor as a film on the metal nitride on the substrate.

Thus, a barrier metal film comprising a film of a metal nitride and a metal film and with diffusion suppressed and adhesion improved can be prepared by forming a metal by plasmas. The barrier metal film can be formed uniformly to a small thickness. Also, the supply line for gases can be simplified, and the number of plasma sources can be decreased, so that the product cost can be reduced. Consequently, the barrier metal film can be formed highly accurately at a high speed and at a low cost with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The first embodiment of the barrier metal film production apparatus and barrier metal film production method of the present invention will be described with reference toFIGS. 1 and 2.FIG. 1is a schematic side view of the barrier metal film production apparatus according to the first embodiment of the present invention.FIG. 2shows details of a substrate on which a barrier metal film has been prepared.

As shown in the drawings, a support platform2is provided near the bottom of a cylindrical chamber1made of, say, a ceramic (an insulating material), and a substrate3is placed on the support platform2. Temperature control means6equipped with a heater4and refrigerant flow-through means5is provided in the support platform2so that the support platform2is controlled to a predetermined temperature (for example, a temperature at which the substrate3is maintained at 100 to 200° C.) by the temperature control means6.

An upper surface of the chamber1is an opening, which is closed with a metal member7, as an etched member, made of a metal (e.g., W, Ti, Ta, or TiSi). The interior of the chamber1closed with the metal member7is maintained at a predetermined pressure by a vacuum device8. A plasma antenna9, as a coiled winding antenna9of plasma generation means, is provided around a cylindrical portion of the chamber1. A matching instrument10and a power source11are connected to the plasma antenna9to supply power.

Nozzles12for supplying a source gas (a Cl2gas diluted with He or Ar to a chlorine concentration of ≦50%, preferably about 10%), containing chlorine as a halogen, to the interior of the chamber1are connected to the cylindrical portion of the chamber1below the metal member7. The nozzle12is open toward the horizontal, and is fed with the source gas via a flow controller13. Fluorine (F), bromine (Br) or iodine (I) can also be applied as the halogen to be incorporated into the source gas.

Slit-shaped opening portions14are formed at a plurality of locations (for example, four locations) in the periphery of a lower part of the cylindrical portion of the chamber1, and one end of a tubular passage15is fixed to each of the opening portions14. A tubular excitation chamber16made of an insulator is provided halfway through the passage15, and a coiled plasma antenna17is provided around the excitation chamber16. The plasma antenna17is connected to a matching instrument18and a power source19to receive power. The plasma antenna17, the matching instrument18and the power source19constitute excitation means. A flow controller20is connected to the other end of the passage15, and an ammonia gas (NH3gas) as a nitrogen gas is supplied into the passage15via the flow controller20.

With the above-described barrier metal film production apparatus, the source gas is supplied through the nozzles12to the interior of the chamber1, and electromagnetic waves are shot from the plasma antenna9into the chamber1. As a result, the Cl2gas is ionized to generate a Cl2gas plasma (source gas plasma)21. The Cl2gas plasma21causes an etching reaction to the metal member7, forming a precursor (MxCly: M is a metal such as W, Ti, Ta or TiSi)22.

Separately, the NH3gas is supplied into the passage15via the flow controller20and fed into the excitation chamber16. By shooting electromagnetic waves from the plasma antenna17into the excitation chamber16, the NH3gas is ionized to generate an NH3gas plasma23. Since a predetermined differential pressure has been established between the pressure inside the chamber and the pressure inside the excitation chamber16by the vacuum device8, the excited ammonia of the NH3gas plasma23in the excitation chamber16is fed to the precursor (MxCly)22inside the chamber1through the opening portion14.

That is, excitation means for exciting the nitrogen gas in the excitation chamber16isolated from the chamber1is constructed. Because of this construction, the metal component of the precursor (MxCly)22and ammonia react to form a metal nitride (MN) (i.e., formation means). At this time, the metal member7and the excitation chamber16are maintained by the plasmas at predetermined temperatures (e.g., 200 to 400° C.) which are higher than the temperature of the substrate3.

The metal nitride (MN) formed within the chamber1is transported toward the substrate3controlled to a low temperature, whereby a thin MN film24is formed on the surface of the substrate3. After the thin MN film24is formed, the supply of the NH3gas and the supply of power to the power source19are cut off. Thus, the precursor (MxCly)22is transported toward the substrate3controlled to a lower temperature than the temperature of the metal member7. The precursor (MxCly)22transported toward the substrate3is converted into only metal (M) ions by a reduction reaction, and directed at the substrate3to form a thin M film25on the thin MN film24on the substrate3. A barrier metal film26is composed of the thin MN film24and the thin M film25(seeFIG. 2).

The reaction for formation of the thin MN film24can be expressed by:
2MCl+2NH3→2MN↓+HCl↑+2H2↑

The reaction for formation of the thin M film25can be expressed by:
2MCl→2M↓+Cl2↑

The gases and the etching products that have not been involved in the reactions are exhausted through an exhaust port27.

The source gas has been described, with the Cl2gas diluted with, say, He or Ar taken as an example. However, the Cl2gas can be used alone, or an HCl gas can also be applied. If the HCl gas is applied, an HCl gas plasma is generated as the source gas plasma. Thus, the source gas may be any gas containing chlorine, and a gas mixture of an HCl gas and a Cl2gas is also usable. As the material for the metal member7, it is possible to use an industrially applicable metal such as Ag, Au, Pt or Si.

The substrate3, on which the barrier metal film26has been formed, is subjected to a film forming device, which forms a thin copper (Cu) film or a thin aluminum (Al) film on the barrier metal film26. Because of the presence of the barrier metal film26, there arise advantages, for example, such that the thin MN film24eliminates diffusion of Cu into the substrate3, and the thin M film25ensures adhesion of Cu.

If the material to be formed as a film is a material unproblematic in terms of adhesion (e.g., Al), or if it is a metal to which the nitride can retain adhesion, the thin M film25can be omitted from the barrier metal film26. Furthermore, the reduction reaction is caused by the temperature difference. However, a reducing gas plasma can be generated separately to produce a reduction reaction.

With the above-described barrier metal film production apparatus, the metal is formed by plasmas to produce the barrier metal film26. Thus, the barrier metal film26can be formed uniformly to a small thickness. Consequently, the barrier metal film26can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate3.

A barrier metal film production apparatus and a barrier metal film production method according to the second embodiment of the present invention will be described with reference toFIGS. 3 to 5.FIG. 3is a schematic side view of the barrier metal film production apparatus according to the second embodiment of the present invention.FIG. 4is a view taken along the arrowed line IV-IV ofFIG. 3.FIG. 5is a view taken along the arrowed line V-V ofFIG. 4. The same members as the members illustrated inFIG. 1are assigned the same numerals, and duplicate explanations are omitted.

An upper surface of the chamber1is an opening, which is closed with a disk-shaped ceiling board30made of an insulating material (for example, a ceramic). An etched member31made of a metal (e.g., W, Ti, Ta or TiSi) is interposed between the opening at the upper surface of the chamber1and the ceiling board30. The etched member31is provided with a ring portion32fitted into the opening at the upper surface of the chamber1. A plurality of (12in the illustrated embodiment) protrusions33, which extend close to the center in the diametrical direction of the chamber1and have the same width, are provided in the circumferential direction on the inner periphery of the ring portion32.

The protrusions33are integrally or removably attached to the ring portion32. Notches (spaces)35formed between the protrusions33are present between the ceiling board30and the interior of the chamber1. The ring portion32is earthed, and the plural protrusions33are electrically connected together and maintained at the same potential. Temperature control means (not shown), such as a heater, is provided in the etched member31to control the temperature of the etched member31to 200 to 400° C., for example.

Second protrusions shorter in the diametrical direction than the protrusions33can be arranged between the protrusions33. Moreover, short protrusions can be arranged between the protrusion33and the second protrusion. By so doing, the area of copper, an object to be etched, can be secured, with an induced current being suppressed.

A planar winding-shaped plasma antenna34, for converting the atmosphere inside the chamber1into a plasma, is provided above the ceiling board30. The plasma antenna34is formed in a planar ring shape parallel to the surface of the ceiling board30. A matching instrument10and a power source11are connected to the plasma antenna34to supply power. The etched member31has the plurality of protrusions33provided in the circumferential direction on the inner periphery of the ring portion32, and includes the notches (spaces)35formed between the protrusions33. Thus, the protrusions33are arranged between the substrate3and the ceiling board30in a discontinuous state relative to the flowing direction of electricity in the plasma antenna34.

With the above-described barrier metal film production apparatus, the source gas is supplied through the nozzles12to the interior of the chamber1, and electromagnetic waves are shot from the plasma antenna34into the chamber1. As a result, the Cl2gas is ionized to generate a Cl2gas plasma (source gas plasma)21. The etched member31, an electric conductor, is present below the plasma antenna34. However, the Cl2gas plasma21occurs stably between the etched member31and the substrate3, namely, below the etched member31, under the following action:

The action by which the Cl2gas plasma21is generated below the etched member31will be described. As shown inFIG. 5, a flow A of electricity in the plasma antenna34of the planar ring shape crosses the protrusions33. At this time, an induced current B occurs on the surface of the protrusion33opposed to the plasma antenna34. Since the notches (spaces)35are present in the etched member31, the induced current B flows onto the lower surface of each protrusion33, forming a flow a in the same direction as the flow A of electricity in the plasma antenna34(Faraday shield).

When the etched member31is viewed from the substrate3, therefore, there is no flow in a direction in which the flow A of electricity in the plasma antenna34is canceled out. Furthermore, the ring portion32is earthed, and the protrusions33are maintained at the same potential. Thus, even though the etched member31, an electric conductor, exists, the electromagnetic wave is reliably thrown from the plasma antenna34into the chamber1. Consequently, the Cl2gas plasma21is stably generated below the etched member31.

Furthermore, plasma generation means composed of a passage15, an excitation chamber16and a plasma antenna17is provided above the support platform2.

The Cl2gas plasma21causes an etching reaction to the etched member31, forming a precursor (MxCly: M is a metal such as W, Ti, Ta or TiSi)22. In the excitation chamber16, the NH3gas is ionized to generate an NH3gas plasma23. The excited ammonia of the NH3gas plasma23in the excitation chamber16is fed to the precursor (MxCly)22inside the chamber1through the opening portion14. Because of this construction, the metal component of the precursor (MxCly)22and ammonia react to form a metal nitride (MN) (formation means). At this time, the etched member31and the excitation chamber16are maintained by the plasmas at predetermined temperatures (e.g., 200 to 400° C.) which are higher than the temperature of the substrate3.

The metal nitride (MN) formed within the chamber1is transported toward the substrate3controlled to a low temperature, whereby a thin MN film24is formed on the surface of the substrate3. After the thin MN film24is formed, the supply of the NH3gas and the supply of power to the power source19are cut off. Thus, the precursor (MxCly)22is transported toward the substrate3controlled to a lower temperature than the temperature of the etched member31. The precursor (MxCly)22transported toward the substrate3is converted into only metal (M) ions by a reduction reaction, and directed at the substrate3to form a thin M film25on the thin MN film24on the substrate3. A barrier metal film26is composed of the thin MN film24and the thin M film25(seeFIG. 2). The gases and the etching products, which have not been involved in the reactions, are exhausted through an exhaust port27.

With the above-described barrier metal film production apparatus, similar to the first embodiment, the metal is formed by plasmas to produce the barrier metal film26. Thus, the barrier metal film26can be formed uniformly to a small thickness. Consequently, the barrier metal film26can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate3.

In addition, the etched member31has the plurality of protrusions33provided in the circumferential direction on the inner periphery of the ring portion32, and includes the notches (spaces)35formed between the protrusions33. Thus, the induced currents generated in the etched member31flow in the same direction as the flowing direction of electricity in the plasma antenna34, when viewed from the substrate3. Therefore, even though the etched member31, an electric conductor, exists below the plasma antenna34, the electromagnetic waves are reliably thrown from the plasma antenna34into the chamber1. Consequently, the Cl2gas plasma21can be stably generated below the etched member31.

A barrier metal film production apparatus and a barrier metal film production method according to the third embodiment of the present invention will be described with reference toFIG. 6.FIG. 6is a schematic side view of the barrier metal film production apparatus according to the third embodiment of the present invention. The same members as the members illustrated inFIGS. 1 and 3are assigned the same numerals, and duplicate explanations are omitted.

The opening of an upper portion of the chamber1is closed with a ceiling board30, for example, made of a ceramic (an insulating material). An etched member41made of a metal (e.g., W, Ti, Ta or TiSi) is provided on a lower surface of the ceiling board30, and the etched member41is of a quadrangular pyramidal shape. Slit-shaped second opening portions42are formed at a plurality of locations (for example, four locations) in the periphery of an upper part of the cylindrical portion of the chamber1, and one end of a tubular second passage43is fixed to the second opening portion42.

A tubular second excitation chamber44made of an insulator is provided halfway through the second passage43, and a coiled second plasma antenna45is provided around the second excitation chamber44. The plasma antenna45is connected to a matching instrument48and a power source49to receive power. The second plasma antenna45, the matching instrument48and the power source49constitute plasma generation means.

A flow controller46is connected to the other end of the second passage43, and a chlorine-containing source gas (a Cl2gas diluted with He or Ar to a chlorine concentration of ≦50%, preferably about 10%) is supplied into the passage43via the flow controller46. By shooting electromagnetic waves from the second plasma antenna45into the second excitation chamber44, the Cl2gas is ionized to generate a Cl2gas plasma (source gas plasma)47. Because of the generation of the Cl2gas plasma47, excited chlorine is fed into the chamber1through the second opening portion42, whereupon the etched member41is etched with excited chlorine.

With the above-described barrier metal film production apparatus, the source gas is supplied into the second passage43via the flow controller46and fed into the second excitation chamber44. By shooting electromagnetic waves from the second plasma antenna45into the second excitation chamber44, the Cl2gas is ionized to generate a Cl2gas plasma (source gas plasma)47. Since a predetermined differential pressure has been established between the pressure inside the chamber1and the pressure inside the second excitation chamber44by the vacuum device8, the excited chlorine of the Cl2gas plasma47in the second excitation chamber44is fed to the etched member41inside the chamber1through the second opening portion42. The excited chlorine causes an etching reaction to the etched member41, forming a precursor (MxCly)22inside the chamber1. At this time, the etched member41is maintained at a predetermined temperature (e.g., 200 to 400° C.), which is higher than the temperature of the substrate3, by a heater50provided in the ceiling board30.

In the excitation chamber16, the NH3gas is ionized to generate an NH3gas plasma23. The excited ammonia of the NH3gas plasma23in the excitation chamber16is fed to the precursor (MxCly)22inside the chamber1through the opening portion14. As a result, the metal component of the precursor (MxCly)22and ammonia react to form a metal nitride (MN). At this time, the excitation chamber16is maintained by the plasma at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate3.

The metal nitride (MN) formed within the chamber1is transported toward the substrate3controlled to a low temperature, whereby a thin MN film24is formed on the surface of the substrate3. After the thin MN film24is formed, the supply of the NH3gas and the supply of power to the power source19are cut off. Thus, the precursor (MxCly)22is transported toward the substrate3controlled to a lower temperature than the temperature of the etched member41. The precursor (MxCly)22transported toward the substrate3is converted into only metal (M) ions by a reduction reaction, and directed at the substrate3to form a thin M film25on the thin MN film24placed on the substrate3. A barrier metal film26is composed of the thin MN film24and the thin M film25(seeFIG. 2). The gases and the etching products that have not been involved in the reactions are exhausted through an exhaust port27.

With the above-described barrier metal film production apparatus, similar to the first embodiment and the second embodiment, the metal is formed by plasmas to produce the barrier metal film26. Thus, the barrier metal film26can be formed uniformly to a small thickness. Consequently, the barrier metal film26can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate3.

Furthermore, the Cl2gas plasma47is generated in the second excitation chamber44isolated from the chamber1. Thus, the substrate3is not exposed to the plasma any more, and the substrate3becomes free from damage from the plasma.

As the means for generating the Cl2gas plasma47in the second excitation chamber44, namely, the means for exciting the source gas to convert it into an excited source gas, it is possible to use microwaves, laser, electron rays, or synchrotron radiation. It is also permissible to form the precursor by heating the metal filament to a high temperature. The construction for isolating the Cl2gas plasma47from the substrate3may be the provision of the second excitation chamber44in the passage43, as stated above, or may be other construction, for example, the isolation of the chamber1.

A barrier metal film production apparatus and a barrier metal film production method according to the fourth embodiment of the present invention will be described with reference toFIG. 7.FIG. 7is a schematic side view of a barrier metal film production apparatus according to the fourth embodiment of the present invention. The same members as the members illustrated inFIG. 1are assigned the same numerals, and duplicate explanations are omitted.

Compared with the barrier metal film production apparatus of the first embodiment shown inFIG. 1, the plasma antenna9is not provided around the cylindrical portion of the chamber1, and the matching instrument10and power source11are connected to the metal member7for supply of power to the metal member7.

With the above-described barrier metal film production apparatus, the source gas is supplied from the nozzle12into the chamber1, and electromagnetic waves are shot from the metal member7into the chamber1, whereby the Cl2gas is ionized to generate a Cl2gas plasma (source gas plasma)21. The Cl2gas plasma21causes an etching reaction to the metal member7, forming a precursor (MxCly)22. At this time, the metal member7is maintained at a temperature (e.g., 200 to 400° C.), which is higher than the temperature of the substrate3, by temperature control means (not shown).

In the excitation chamber16, the NH3gas is ionized to generate an NH3gas plasma23. The excited ammonia of the NH3gas plasma23in the excitation chamber16is fed to the precursor (MxCly)22inside the chamber1through the opening portion14. As a result, the metal component of the precursor (MxCly)22and ammonia react to form a metal nitride (MN). At this time, the excitation chamber16is maintained by the plasma at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate3.

The metal nitride (MN) formed within the chamber1is transported toward the substrate3controlled to a low temperature, whereby a thin MN film24is formed on the surface of the substrate3. After the thin MN film24is formed, the supply of the NH3gas and the supply of power to the power source19are cut off. Thus, the precursor (MxCly)22is transported toward the substrate3controlled to a lower temperature than the temperature of the metal member7. The precursor (MxCly)22transported toward the substrate3is converted into only metal (M) ions by a reduction reaction, and directed at the substrate3to form a thin M film25on the thin MN film24placed on the substrate3. A barrier metal film26is composed of the thin MN film24and the thin M film25(seeFIG. 2). The gases and the etching products that have not been involved in the reactions are exhausted through an exhaust port27.

With the above-described barrier metal film production apparatus, similar to the first embodiment to the third embodiment, the metal is formed by plasmas to produce the barrier metal film26. Thus, the barrier metal film26can be formed uniformly to a small thickness. Consequently, the barrier metal film26can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate3.

Furthermore, the metal member7itself is applied as an electrode for plasma generation. Thus, the plasma antenna9need not be provided around the cylindrical portion of the chamber1, and the degree of freedom of the construction in the surroundings can be increased.

A barrier metal film production apparatus and a barrier metal film production method according to the fifth embodiment of the present invention will be described with reference toFIG. 8.FIG. 8is a schematic side view of the barrier metal film production apparatus according to the fifth embodiment of the present invention. The same members as the members illustrated inFIG. 1are assigned the same numerals, and duplicate explanations are omitted.

Compared with the first embodiment shown inFIG. 1, the barrier metal film production apparatus shown inFIG. 8lacks the opening portion14, passage15, excitation chamber16, plasma antenna17, matching instrument18, power source19and flow controller20. Nozzles12for supplying a gas mixture of a source gas (Cl2gas) and a nitrogen gas (N2gas) as a nitrogen gas to the interior of the chamber1are connected to the cylindrical portion of the chamber1. The Cl2gas and the N2gas are mixed in a mixed gas flow controller81, and the gas mixture of the Cl2gas and the N2gas is supplied to the nozzle12via the mixed gas flow controller81. Other constructions are the same as in the first embodiment.

With the above-described barrier metal film production apparatus, the mixed gas comprising the Cl2gas and the N2gas is supplied through the nozzles12to the interior of the chamber1, and electromagnetic waves are shot from the plasma antenna9into the chamber1. As a result, the Cl2gas and the N2gas are ionized to generate a Cl2gas/N2gas plasma82. The Cl2gas/N2gas plasma82causes an etching reaction to the metal member7, forming a precursor (MxCly: M is a metal such as W, Ti, Ta or TiSi)22. Also, the precursor22and N2react to form a metal nitride (MN). At this time, the metal member7is maintained by the plasma (or temperature control means (not shown)) at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate3.

The metal nitride (MN) formed within the chamber1is transported toward the substrate3controlled to a low temperature, whereby a thin MN film24is formed on the surface of the substrate3. After the thin MN film24is formed, the supply of the N2gas to the mixed gas flow controller81is cut off. Thus, the precursor (MxCly)22is transported toward the substrate3controlled to a lower temperature than the temperature of the metal member7. The precursor (MxCly)22transported toward the substrate3is converted into only metal (M) ions by a reduction reaction, and directed at the substrate3to form a thin M film25on the surface of the substrate3. A barrier metal film26is composed of the thin MN film24and the thin M film25(seeFIG. 2).

The substrate3, on which the barrier metal film26has been formed, is to have a thin copper (Cu) film or a thin aluminum (Al) film formed on the barrier metal film26by a film forming device. Because of the presence of the barrier metal film26, there arise advantages, for example, such that the thin MN film24eliminates diffusion of Cu into the substrate3, and the thin M film25ensures adhesion of Cu.

If the material to be formed as a film is a material unproblematic in terms of adhesion (e.g., Al), or if it is a metal to which the nitride can retain adhesion, the thin M film25can be omitted from the barrier metal film26.

With the above-described barrier metal film production apparatus, the same effects as in the first embodiment are obtained. In addition, the supply line for the gases can be simplified, and the number of the plasma sources can be decreased. Thus, the cost of the product can be reduced.

The sixth embodiment of a barrier metal film production apparatus and a barrier metal film production method according to the present invention will be described with reference toFIG. 9.FIG. 9is a schematic side view of the barrier metal film production apparatus according to the sixth embodiment of the present invention. The same members as in the second and fifth embodiments illustrated inFIGS. 3 to 5and8are assigned the same numerals, and duplicate explanations are omitted.

Compared with the second embodiment shown inFIG. 3, the barrier metal film production apparatus shown inFIG. 9lacks the opening portion14, passage15, excitation chamber16, plasma antenna17, matching instrument18, power source19and flow controller20. Nozzles12for supplying a gas mixture of a source gas (Cl2gas) and a nitrogen gas (N2gas) as a nitrogen gas to the interior of the chamber1are connected to the cylindrical portion of the chamber1. The Cl2gas and the N2gas are mixed in a mixed gas flow controller81, and the gas mixture of the Cl2gas and the N2gas is supplied to the nozzle12via the mixed gas flow controller81. Other constructions are the same as in the second embodiment.

With the above-described barrier metal film production apparatus, the mixed gas comprising the Cl2gas and the N2gas is supplied through the nozzles12to the interior of the chamber1, and electromagnetic waves are shot from the plasma antenna34into the chamber1. As a result, the Cl2gas and the N2gas are ionized to generate a Cl2gas/N2gas plasma82. The etched member31, an electric conductor, is present below the plasma antenna34. As stated earlier, however, the Cl2gas/N2gas plasma82occurs stably between the etched member31and the substrate3, namely, below the etched member31.

The Cl2gas/N2gas plasma82causes an etching reaction to the etched member31, forming a precursor (MxCly: M is a metal such as W, Ti, Ta or TiSi)22. Also, the precursor22and N2react to form a metal nitride (MN). At this time, the etched member31is maintained by the plasma (or temperature control means (not shown)) at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate3.

The metal nitride (MN) formed within the chamber1is transported toward the substrate3controlled to a low temperature, whereby a thin MN film24is formed on the surface of the substrate3. After the thin MN film24is formed, the supply of the N2gas to the mixed gas flow controller81is cut off. Thus, the precursor (MxCly)22is transported toward the substrate3controlled to a lower temperature than the temperature of the etched member31. The precursor (MxCly)22transported toward the substrate3is converted into only metal (M) ions by a reduction reaction, and directed at the substrate3to form a thin M film25on the thin MN film24on the substrate3. A barrier metal film26is composed of the thin MN film24and the thin M film25(seeFIG. 2).

The substrate3, on which the barrier metal film26has been formed, is to have a thin copper (Cu) film or a thin aluminum (Al) film formed on the barrier metal film26by a film forming device. Because of the presence of the barrier metal film26, there arise advantages, for example, such that the thin MN film24eliminates diffusion of Cu into the substrate3, and the thin M film25ensures adhesion of Cu.

If the material to be formed as a film is a material unproblematic in terms of adhesion (e.g., Al), or if it is a metal to which the nitride can retain adhesion, the thin M film25can be omitted from the barrier metal film26.

With the above-described barrier metal film production apparatus, the same effects as in the second embodiment are obtained. In addition, the supply line for the gases can be simplified, and the number of the plasma sources can be decreased. Thus, the cost of the product can be reduced.

The seventh embodiment of a barrier metal film production apparatus and a barrier metal film production method according to the present invention will be described with reference toFIG. 10.FIG. 10is a schematic side view of the barrier metal film production apparatus according to the seventh embodiment of the present invention. The same members as in the third and fifth embodiments illustrated inFIGS. 6 and 8are assigned the same numerals, and duplicate explanations are omitted.

Compared with the third embodiment shown inFIG. 6, the barrier metal film production apparatus shown inFIG. 10lacks the opening portion14, passage15, excitation chamber16, plasma antenna17, matching instrument18, power source19and flow controller20. A gas mixture of a source gas (Cl2gas) and a nitrogen gas (N2gas) as a nitrogen gas is supplied from a mixed gas flow controller81to a second excitation chamber44. Other constructions are the same as in the third embodiment.

With the above-described barrier metal film production apparatus, the mixed gas comprising the Cl2gas and the N2gas is supplied into a second passage43via the mixed gas flow controller81, and fed into the second excitation chamber44. Electromagnetic waves are shot from a second plasma antenna45into the second excitation chamber44. As a result, the Cl2gas and the N2gas are ionized to generate a Cl2gas/N2gas plasma82. Since a predetermined differential pressure has been established between the pressure inside the chamber and the pressure inside the second excitation chamber44by the vacuum device8, the excited chlorine and excited nitrogen of the Cl2gas/N2gas plasma82in the second excitation chamber44are fed to the etched member41inside the chamber1through the second opening portion42. The excited chlorine causes an etching reaction to the etched member41, forming a precursor (MxCly)22inside the chamber1. Also, the precursor22and the excited nitrogen react to form a metal nitride (MN). At this time, the etched member41is maintained at a predetermined temperature (e.g., 200 to 400° C.), which is higher than the temperature of the substrate3, by a heater50provided in a ceiling board30.

The metal nitride (MN) formed within the chamber1is transported toward the substrate3controlled to a low temperature, whereby a thin MN film24is formed on the surface of the substrate3. After the thin MN film24is formed, the supply of the N2gas to the mixed gas flow controller81is cut off. Thus, the precursor (MxCly)22is transported toward the substrate3controlled to a lower temperature than the temperature of the etched member41. The precursor (MxCly)22transported toward the substrate3is converted into only metal (M) ions by a reduction reaction, and directed at the substrate3to form a thin M film25on the thin MN film24on the substrate3. A barrier metal film26is composed of the thin MN film24and the thin M film25(seeFIG. 2).

The substrate3, on which the barrier metal film26has been formed, is to have a thin copper (Cu) film or a thin aluminum (Al) film formed on the barrier metal film26by a film forming device. Because of the presence of the barrier metal film26, there arise advantages, for example, such that the thin MN film24eliminates diffusion of Cu into the substrate3, and the thin M film25ensures adhesion of Cu.

If the material to be formed as a film is a material unproblematic in terms of adhesion (e.g., Al), or if it is a metal to which the nitride can retain adhesion, the thin M film25can be omitted from the barrier metal film26.

With the above-described barrier metal film production apparatus, the same effects as in the third embodiment are obtained. In addition, the supply line for the gases can be simplified, and the number of the plasma sources can be decreased. Thus, the cost of the product can be reduced.

The eighth embodiment of a barrier metal film production apparatus and a barrier metal film production method according to the present invention will be described with reference toFIG. 11.FIG. 11is a schematic side view of the barrier metal film production apparatus according to the eighth embodiment of the present invention. The same members as in the fourth embodiment and the fifth embodiment illustrated inFIGS. 7 and 8are assigned the same numerals, and duplicate explanations are omitted.

Compared with the fourth embodiment shown inFIG. 7, the barrier metal film production apparatus shown inFIG. 11lacks the opening portion14, passage15, excitation chamber16, plasma antenna17, matching instrument18, power source19and flow controller20. Nozzles12for supplying a gas mixture of a source gas (Cl2gas) and a nitrogen gas (N2gas) as a nitrogen gas to the interior of the chamber1are connected to the cylindrical portion of the chamber1. The Cl2gas and the N2gas are mixed in a mixed gas flow controller81, and the gas mixture of the Cl2gas and the N2gas is supplied to the nozzle12via the mixed gas flow controller81. Other constructions are the same as in the fourth embodiment.

With the above-described barrier metal film production apparatus, the mixed gas comprising the Cl2gas and the N2gas is supplied through the nozzles12to the interior of the chamber1, and electromagnetic waves are shot from the metal member7into the chamber1. As a result, the Cl2gas and the N2gas are ionized to generate a Cl2gas/N2gas plasma82. The Cl2gas/N2gas plasma82causes an etching reaction to the metal member7, forming a precursor (MxCly: M is a metal such as W, Ti, Ta or TiSi)22. Also, the precursor22and N2react to form a metal nitride (MN). At this time, the metal member7is maintained by the plasma (or temperature control means (not shown)) at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate3.

The metal nitride (MN) formed within the chamber1is transported toward the substrate3controlled to a low temperature, whereby a thin MN film24is formed on the surface of the substrate3. After the thin MN film24is formed, the supply of the N2gas to the mixed gas flow controller81is cut off. Thus, the precursor (MxCly)22is transported toward the substrate3controlled to a lower temperature than the temperature of the metal member7. The precursor (MxCly)22transported toward the substrate3is converted into only metal (M) ions by a reduction reaction, and directed at the substrate3to form a thin M film25on the thin MN film24on the substrate3. A barrier metal film26is composed of the thin MN film24and the thin M film25(seeFIG. 2).

The substrate3, on which the barrier metal film26has been formed, is to have a thin copper (Cu) film or a thin aluminum (Al) film formed on the barrier metal film26by a film forming device. Because of the presence of the barrier metal film26, there arise advantages, for example, such that the thin MN film24eliminates diffusion of Cu into the substrate3, and the thin M film25ensures adhesion of Cu.

If the material to be formed as a film is a material unproblematic in terms of adhesion (e.g., Al), or if it is a metal to which the nitride can retain adhesion, the thin M film25can be omitted from the barrier metal film26.

With the above-described barrier metal film production apparatus, the same effects as in the fourth embodiment are obtained. In addition, the supply line for the gases can be simplified, and the number of the plasma sources can be decreased. Thus, the cost of the product can be reduced.

In the foregoing fifth to eighth embodiments, the N2gas is mixed with the Cl2gas in the mixed gas flow controller81, and the gas mixture is supplied into the chamber1. However, the N2gas and the Cl2gas can be supplied through separate nozzles. Also, ammonia can be applied as the nitrogen-containing gas.

While the present invention has been described by the foregoing embodiments, it is to be understood that the invention is not limited thereby, but may be varied in many other ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the appended claims.