WO2011162255A1 - Process for production of barrier film, and process for production of metal wiring film - Google Patents

Process for production of barrier film, and process for production of metal wiring film Download PDF

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Publication number
WO2011162255A1
WO2011162255A1 PCT/JP2011/064158 JP2011064158W WO2011162255A1 WO 2011162255 A1 WO2011162255 A1 WO 2011162255A1 JP 2011064158 W JP2011064158 W JP 2011064158W WO 2011162255 A1 WO2011162255 A1 WO 2011162255A1
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Prior art keywords
film
substrate
barrier film
metal wiring
hydrogen
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PCT/JP2011/064158
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French (fr)
Japanese (ja)
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雅通 原田
洋平 小川
正一郎 熊本
晃子 山本
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株式会社アルバック
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Priority to JP2012521480A priority Critical patent/JPWO2011162255A1/en
Publication of WO2011162255A1 publication Critical patent/WO2011162255A1/en

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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
    • C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
    • C23C16/34—Nitrides
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
    • C23C16/455—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
    • C23C16/45523—Pulsed gas flow or change of composition over time
    • C23C16/45525—Atomic layer deposition [ALD]
    • C23C16/45527—Atomic layer deposition [ALD] characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations
    • C23C16/45536—Use of plasma, radiation or electromagnetic fields
    • C23C16/4554—Plasma being used non-continuously in between ALD reactions
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/56—After-treatment
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/28—Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268
    • H01L21/283—Deposition of conductive or insulating materials for electrodes conducting electric current
    • H01L21/285—Deposition of conductive or insulating materials for electrodes conducting electric current from a gas or vapour, e.g. condensation
    • H01L21/28506—Deposition of conductive or insulating materials for electrodes conducting electric current from a gas or vapour, e.g. condensation of conductive layers
    • H01L21/28512—Deposition of conductive or insulating materials for electrodes conducting electric current from a gas or vapour, e.g. condensation of conductive layers on semiconductor bodies comprising elements of Group IV of the Periodic System
    • H01L21/28556—Deposition of conductive or insulating materials for electrodes conducting electric current from a gas or vapour, e.g. condensation of conductive layers on semiconductor bodies comprising elements of Group IV of the Periodic System by chemical means, e.g. CVD, LPCVD, PECVD, laser CVD
    • H01L21/28562—Selective deposition
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
    • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
    • H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
    • H01L21/76838—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the conductors
    • H01L21/76841—Barrier, adhesion or liner layers
    • H01L21/76843—Barrier, adhesion or liner layers formed in openings in a dielectric
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
    • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
    • H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
    • H01L21/76838—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the conductors
    • H01L21/76841—Barrier, adhesion or liner layers
    • H01L21/76853—Barrier, adhesion or liner layers characterized by particular after-treatment steps
    • H01L21/76861—Post-treatment or after-treatment not introducing additional chemical elements into the layer
    • H01L21/76862—Bombardment with particles, e.g. treatment in noble gas plasmas; UV irradiation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
    • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
    • H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
    • H01L21/76838—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the conductors
    • H01L21/76877—Filling of holes, grooves or trenches, e.g. vias, with conductive material

Definitions

  • the present invention relates to a method for forming a barrier film and a method for forming a metal wiring film, and in particular, a method for forming a barrier film as a base of a metal wiring film such as a Cu film formed in a fine trench or hole, and a metal wiring film It relates to a forming method.
  • metal interconnections of 0.05 ⁇ m or less play an important role.
  • Aluminum (Al) is widely used for metal interconnections because of its excellent electrical characteristics and low cost.
  • the limit is reached as the device density and wiring length increase. That is, it has been found that in devices of 0.18 ⁇ m or less, the wiring delay determines the speeding up of the device. Therefore, there is a need for new metal interconnects that meet the demands of next generation devices.
  • Copper (Cu) has been studied as a wiring metal instead of Al and has been partially put into practical use.
  • the resistivity of Cu (1.67 ⁇ 10 ⁇ 6 ⁇ ⁇ cm) is about 60% lower than that of Al (2.66 ⁇ 10 ⁇ 6 ⁇ ⁇ cm), so there is less wiring delay. Speed up the device.
  • Cu is an element heavier than Al, it has high resistance to electromigration and stress migration, and can realize highly reliable wiring.
  • Cu is diffused into an insulating film formed on a wafer by a physical vapor deposition (PVD) method on a substrate such as a wafer in which trenches and holes are formed.
  • PVD physical vapor deposition
  • a method of forming a barrier film such as a metal nitride film for suppressing the deposition, forming a seed film for electroplating, and then embedding trenches or holes by an electroplating method is generally used. It is used for.
  • the miniaturization of the Cu wiring makes the asymmetry between the central portion and the end portion of the wafer or the like, or the overhang of the barrier film or the seed film becomes remarkable, and there is a problem that voids are generated during electroplating.
  • a seed film 103 is formed on a barrier film 102 formed on a substrate 101 provided with a ⁇ 32 nm hole or trench by a PVD method.
  • the hole is formed, the upper part of the hole or trench is overhanged (part A) and the opening of the hole or the like is narrowed.
  • the plating solution is difficult to enter.
  • the adhesion between the Cu film and the barrier film is not good, there is a problem that the Cu film is sucked up as the Cu film is buried, and voids (B portion) are generated in the Cu film.
  • the seed film 103 cannot be uniformly and symmetrically formed by PVD on the side surfaces of holes or the like (C portion), and due to the asymmetry of this barrier film, There is also a problem that voids (D portion) are generated in the Cu film 104 to be embedded in the next plating step.
  • the chemical vapor deposition (CVD) method and the ALD (Atomic Layer Deposition) method are excellent in step coverage, so there is no problem of the above asymmetry and overhang. It is thought that it can cope with the conversion.
  • the barrier film is formed by the CVD method or the ALD method
  • the adhesion with the Cu wiring formed on the barrier film is insufficient.
  • Such a problem is not limited to the case where Cu is used as the wiring, but also exists in metal wiring other than Cu.
  • Such a problem also exists in the current mainstream method of forming a Cu wiring film by electroplating after forming a Cu seed film on the barrier film by the PVD method, but the Cu wiring is directly formed on the barrier film by the CVD method. It is more noticeable when formed.
  • Patent Document 1 discloses a technique of irradiating plasma of hydrogen gas and silane-based gas when laminating metal nitride films, but hydrogen is not used alone, and metal nitride films are not used. Further, it does not pay attention to the adhesiveness between the film and the metal wiring film formed thereon.
  • An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a method for forming a barrier film and a method for forming a metal wiring film that are excellent in adhesion to the metal wiring film.
  • a metal nitride film serving as a barrier film is formed by a CVD method or an ALD method on a substrate in which holes or trenches are formed, and a bias voltage is applied to the substrate side.
  • the surface of the metal nitride film is irradiated with hydrogen plasma or hydrogen radicals while applying.
  • the bias voltage applied to the substrate side is preferably applied to the substrate side by supplying power so that the power density is 0.25 to 1.5 W / cm 2 .
  • the temperature of the substrate when the surface of the metal nitride film is irradiated with hydrogen plasma or hydrogen radicals is preferably 180 ° C. to 350 ° C.
  • the metal nitride film may be a film made of titanium nitride, tungsten nitride, tantalum nitride, zirconium nitride, or vanadium nitride.
  • the method for forming a metal wiring film according to the present invention is characterized in that a metal wiring film is formed by a CVD method or a PVD method on a barrier film in a hole or a trench formed by the barrier film forming method.
  • the metal wiring film may be a film made of copper, aluminum or tungsten.
  • the substrate temperature when forming the metal wiring film on the barrier film is preferably 170 ° C. to 190 ° C.
  • a metal nitride film serving as a barrier film is formed on a substrate on which holes or trenches are formed by a CVD method or an ALD method.
  • the barrier film is formed by irradiating the surface of the metal nitride film with hydrogen plasma or hydrogen radicals while applying a bias voltage to the substrate side by supplying electric power so as to be 0.25 to 1.5 W / cm 2.
  • a metal wiring film is formed by CVD or PVD on the barrier film formed in the hole or trench after formation.
  • the present invention it is possible to form a barrier film having excellent adhesion to the metal wiring film, and to suppress the peeling of the metal wiring film formed on the barrier film.
  • FIG. 6 It is a schematic diagram which shows the void generation
  • a metal nitride film to be a barrier film is formed by CVD or ALD on a substrate in which holes or trenches are formed, and metal nitridation is performed while applying a bias voltage to the substrate side.
  • the surface of the material film is irradiated with hydrogen plasma or hydrogen radicals, and the metal wiring film forming method of the present invention further forms a metal wiring film on the barrier film.
  • a metal nitride film serving as a barrier film is formed by CVD or ALD in a hole or trench on a substrate such as a wafer.
  • the size of the hole or trench is not particularly limited.
  • Examples of the metal nitride film formed by the CVD method or the ALD method include TiN, TaN, WN, ZrN, and VN.
  • the CVD (Chemical Vapor Deposition) method refers to a method in which a raw material gas is flowed over a substrate and a reaction product of the raw material gas is deposited on the substrate.
  • ALD (Atomic Layer Deposition) method is Two or more source gases are alternately supplied to the substrate surface and reacted to form a film on the substrate.
  • a source gas for the ALD method or the CVD method for example, TiCl 4 gas, NH 3 gas, and H 2 gas may be used in the case of a TiN film.
  • a metal nitride film can be efficiently formed by using a CVD method (Cat-CVD method) or an ALD method (Cat-ALD method) using a catalyst.
  • the surface of the metal nitride film is irradiated with hydrogen plasma or hydrogen radicals while applying a bias voltage to the substrate.
  • a barrier film made of a metal nitride film and the barrier film are formed as shown in Examples described later. Adhesion with the metal wiring film formed on the top is improved.
  • the surface of the metal nitride film is irradiated with hydrogen plasma or hydrogen radicals while applying a bias voltage to the substrate, so that impurities such as chlorine, fluorine, and carbon contained in the material of the metal nitride film become hydrogen ions. Since it reacts with hydrogen radicals to form a gas and is removed from the surface of the metal nitride film, it is assumed that the adhesion is improved.
  • the metal nitridation formed by the CVD method or the ALD method is performed.
  • impurities such as chlorine, fluorine, and carbon derived from the material of the material film remain on the barrier film
  • film peeling occurs in the CMP process.
  • device malfunction occurs due to insufficient high via resistance and electromigration resistance.
  • impurities such as chlorine, fluorine, and carbon are removed, adhesion is improved and film peeling in the CMP process can be suppressed.
  • FIGS. 2A and 2B show a configuration example of an apparatus for performing an operation of irradiating the surface of the metal nitride film with hydrogen plasma or hydrogen radical while applying a bias voltage to such a substrate.
  • FIG. 2 (a) is a schematic diagram showing one configuration of a hydrogen plasma processing apparatus for irradiating hydrogen plasma
  • the hydrogen plasma processing apparatus 20 has a vacuum chamber 22 provided with a vacuum exhaust means 21 such as a pump.
  • a substrate support 24 having a quartz plate 23 provided on the upper surface is installed in the vacuum chamber 22, and a barrier film (not shown) is formed on the substrate support 24 (and thus the quartz plate 23).
  • a substrate S is placed.
  • the quartz plate 23 is provided to prevent the substrate support 24 from being scraped by hydrogen plasma.
  • hydrogen gas introduction means (not shown) for introducing hydrogen gas into the vacuum chamber 22 is provided on the ceiling or side wall of the vacuum chamber 22.
  • a heating means 25 such as a lamp heater for heating the substrate S is provided outside the ceiling portion of the vacuum chamber 22.
  • a quartz window 26 that allows heat from the heating means 25 to pass therethrough is provided at the ceiling of the vacuum chamber 22.
  • the substrate support 24 is connected to a high frequency power source 27 for applying a bias voltage to the substrate support 24 (and thus the substrate S).
  • the high frequency power supply 27 is configured to generate plasma P above the vacuum chamber 22.
  • a substrate S on which a barrier film made of a metal nitride film is formed is placed on the substrate support 24. Then, the substrate S is heated to a predetermined temperature by the heating means 25 and a predetermined voltage is applied to the substrate S from the high frequency power source 27. Further, the inside of the vacuum chamber 22 is evacuated to a predetermined degree of vacuum by the evacuation means 21. Then, hydrogen gas is introduced into the vacuum chamber 22 from the hydrogen gas introducing means, thereby generating hydrogen plasma, and irradiating the hydrogen plasma to the barrier film made of the metal nitride film formed on the substrate S.
  • the hydrogen plasma processing apparatus 40 includes a vacuum chamber 42 provided with a vacuum exhaust means 41 such as a pump. Have In the vacuum chamber 42, a substrate support table 44 having an upper surface provided with heating means 45 such as an AlN heater is installed, and the substrate S on which a barrier film (not shown) is formed on the heating means 45. Is placed. In addition, a quartz plate 43 is provided at the edge of the upper surface of the heating unit 45 where the substrate S is not placed. The quartz plate 43 is provided to prevent the substrate support 44 from being scraped by hydrogen plasma.
  • hydrogen gas introduction means for introducing hydrogen gas into the vacuum chamber 42 is provided on the ceiling or side wall of the vacuum chamber 42.
  • the substrate support 44 is connected to a high frequency power supply 47 for applying a bias voltage to the substrate support 24 (and thus the substrate S).
  • an antenna coil 49 connected to a high frequency power supply 48 is provided outside the side surface of the vacuum chamber 42, and high frequency is applied to the antenna coil 49 to perform high-density plasma discharge.
  • the plasma P is generated.
  • an inner surface of the vacuum chamber 42 is provided with a removable attachment plate 50 such as detachable alumina that prevents the inner wall of the vacuum chamber 42 from being soiled.
  • a substrate S on which a barrier film made of a metal nitride film is formed is placed on a heating means 45 provided on a substrate support base 44. To do. Then, the substrate S is heated to a predetermined temperature by the heating means 45 and a predetermined voltage is applied to the substrate S from the high frequency power source 47. Further, the inside of the vacuum chamber 42 is evacuated to a predetermined degree of vacuum by the evacuation means 41. Then, a voltage is applied to the antenna coil 49 from the high frequency power supply 48 and hydrogen gas is introduced into the vacuum chamber 42 from the hydrogen gas introducing means, thereby generating a high-density hydrogen plasma. The barrier film made of the formed metal nitride film is irradiated.
  • FIG. 3 shows a schematic diagram of one configuration of a hydrogen radical processing apparatus 60 that generates and irradiates hydrogen radicals with a catalyst.
  • the hydrogen radical processing apparatus 60 has a vacuum chamber 62 provided with a vacuum exhaust means 61 such as a pump.
  • a substrate support base 64 having a heating means 65 such as a heater provided on the upper surface is provided.
  • a substrate S on which a barrier film (not shown) is formed on the heating means 65 is provided.
  • a hydrogen gas introducing means 66 such as a shower plate for introducing hydrogen gas or carrier gas (for example, argon) into the vacuum chamber 62 is provided at the ceiling of the vacuum chamber 62.
  • the substrate support base 64 is provided with a high frequency power supply 67 for applying a bias voltage to the substrate support base 64 (and consequently the substrate S).
  • a catalyst wire 70 made of tungsten or the like is provided above the vacuum chamber 62 so as to face the hydrogen gas introduction means 66 so as to contact the introduced hydrogen gas.
  • the catalyst wire 70 is configured to generate radicals between the substrate support base 64 (and consequently the substrate S) and the hydrogen gas introducing means 66.
  • the catalyst wire 70 can be energized so that the catalyst wire 70 is heated.
  • a substrate S on which a barrier film made of a metal nitride film is formed is placed on a heating means 65 provided on a substrate support base 64. To do. Then, the substrate S is heated to a predetermined temperature by the heating means 65 and a predetermined voltage is applied to the substrate S from the high frequency power source 67. Further, the inside of the vacuum chamber 62 is evacuated to a predetermined degree of vacuum by the evacuating means 61, and the catalyst line 70 is energized to heat the catalyst line 70 to a predetermined temperature.
  • hydrogen gas is introduced into the vacuum chamber 62 from the hydrogen gas introducing means 66, hydrogen radicals are generated by bringing the hydrogen gas into contact with the catalyst wire 70, and the hydrogen radicals are formed on the substrate S. Irradiate a barrier film made of a film.
  • a rare gas such as argon or helium or an inert gas such as nitrogen gas is introduced before the hydrogen gas is introduced into the vacuum chamber 62. It may be.
  • the hydrogen plasma processing apparatuses 20 and 40 and the hydrogen radical processing apparatus 60 can be used as a CVD apparatus or an ALD apparatus for forming a metal nitride film by providing means for adjusting the gas to be supplied.
  • the formation of the metal nitride film and the irradiation with hydrogen plasma or hydrogen radical can be performed with the same apparatus.
  • a first source gas supply unit that supplies a first source gas and a second source gas supply unit that supplies a second source gas are provided on the ceiling or side wall of the vacuum chamber.
  • a substrate S is placed on a substrate support, and a first source gas and a second source gas are alternately introduced into a vacuum chamber, thereby forming a metal nitride film on the substrate by the ALD method. can do.
  • a CVD apparatus or ALD apparatus is provided with a deposition plate for preventing contamination of the inner wall of the vacuum chamber on the inner surface of the vacuum chamber, a vacuum by CVD or ALD is used. Contamination of the chamber wall surface can be suppressed.
  • Specific conditions for irradiating the substrate with hydrogen plasma and hydrogen radicals are not particularly limited.
  • hydrogen ions or hydrogen radicals may be generated by converting hydrogen gas into plasma using an RF power source of 13.56 MHz.
  • Specific processing condition examples are hydrogen: 100 to 400 sccm, argon: 0 to 200 sccm, pressure: 1 to 100 Pa, and irradiation time: about 10 to 100 seconds.
  • the temperature of the substrate S is preferably 180 ° C. or higher, for example, 180 ° C. to 350 ° C.
  • the metal nitride film is formed by CVD or ALD to complete the barrier film, only the outermost surface is irradiated with hydrogen plasma or hydrogen radicals while applying a bias voltage to the substrate.
  • hydrogen plasma or hydrogen radicals may be irradiated while applying a bias voltage to the substrate. That is, the operation of irradiating with hydrogen plasma or hydrogen radicals after sequentially supplying two or more source gases to the substrate may be repeated.
  • the bias voltage applied to the substrate when the surface of the metal nitride film is irradiated with hydrogen plasma or hydrogen radicals is obtained by supplying power to the substrate so that the power density is 0.25 to 1.5 W / cm 2.
  • a bias voltage is applied to the substrate side by supplying power so that the power density is 0.25 to 1.5 W / cm 2 , particularly between the barrier film and the metal wiring film.
  • the adhesiveness is remarkably excellent. If it is less than 0.25 W / cm 2 , the improvement in adhesion is insufficient, and if it exceeds 1.5 W / cm 2 , hydrogen tends to be implanted into the metal nitride film, which is not preferable.
  • the power density is a value obtained by dividing the power supplied to the substrate by the substrate area.
  • the power supplied to the substrate may be about 200 W to 1000 W, for example.
  • the bias voltage is applied in order to draw hydrogen ions generated by the hydrogen plasma to the substrate side, and must be applied to the substrate side.
  • the source gas for irradiating the hydrogen plasma or the hydrogen radical needs to be only hydrogen gas.
  • a silane-based gas or a hydrogen nitride gas is used in addition to the hydrogen gas, the present invention is used.
  • the silane-based gas may be decomposed by plasma and a high-resistance Si film may be deposited.
  • the hydrogen nitride gas is used, the metal nitride film becomes rich in nitrogen and may increase in resistance.
  • a detoxification facility for detoxifying silane-based gas and the like is necessary.
  • a metal wiring film is formed on the barrier film.
  • the metal of the metal wiring film is not particularly limited, and examples thereof include Cu, Al, and W. From the viewpoint of miniaturization, Cu is preferable.
  • a method for forming the metal wiring film is not particularly limited, and for example, a CVD method, a PVD method, or a plating method may be used. From the viewpoint of miniaturization, the CVD method is preferable.
  • the CVD method an organometallic compound containing Cu is used as a raw material, which is decomposed by heat or plasma to form a film.
  • the organometallic compound used include cupra select (Cupra Select, Cu +1 (hfac) (tmvs)), Cu (SOPD) 2 , Cu (edmod) 2 , and Cu (ibpm) 2 manufactured by SCHUMAHER. Can be mentioned.
  • hfac is a hexafluoroacetylacetonate anion
  • tmvs is trimethylvinylsilane
  • SOPD is 2,6-dimethyl-2- (trimethylsilyloxy) -3,5-heptanedionate
  • edmod is ethyldimethyloctanedionate
  • ibpm is isobutyrylpirate. It is an abbreviation for valoylmethanate and contains fluorine, chlorine, carbon, etc. in the molecule.
  • the temperature of the substrate is preferably 170 to 190 ° C. when a Cu film is formed as a metal wiring film. If the temperature is lower than 170 ° C., the raw material is not sufficiently decomposed and the metal wiring film contains a large amount of impurities F and C, which is not suitable for practical use. This is because there is a tendency to end up.
  • the barrier film formation and the metal wiring film formation are performed in the same apparatus or in the atmosphere. It is preferable to carry out in a consistent vacuum, for example, by transporting the substrate without touching it.
  • a substrate having a hole is used and a metal wiring film is formed in the hole.
  • a substrate having a trench A substrate in which an insulator film such as SiO 2 is provided on a silicon wafer or the like and a trench or a hole is provided in the insulator film may be used.
  • a planar substrate without a trench or a hole may be used.
  • Example 1 a barrier film made of TiN having a thickness of 10 nm was formed on a silicon wafer having a diameter of 300 mm by the Cat-ALD method.
  • the Cat-ALD method uses a Cat-ALD apparatus, TiCl 4 flow rate 0.2 g / min, carrier (nitrogen) flow rate 200 sccm, H 2 flow rate 400 sccm, NH 3 flow rate 600 sccm, substrate temperature 350 ° C., Cat (tungsten). The measurement was performed at a temperature of 1750 ° C.
  • the surface of the barrier film made of TiN was irradiated with hydrogen plasma while applying a bias voltage to the substrate.
  • Irradiation with hydrogen plasma is performed at an H 2 flow rate of 230 sccm, a pressure of 1.0 Pa, an antenna coil voltage of 1900 W, power supplied to the substrate to apply a bias voltage to the substrate (hereinafter also referred to as “substrate bias value”) 200 W, Plasma was discharged for 60 seconds under the condition of a substrate temperature of 350 ° C. Note that since 200 W of power is supplied to the substrate, the power density is 0.28 W / cm 2 .
  • the film was transported to a device for forming a metal wiring film without being exposed to the atmosphere (vacuum continuous transport), and a metal wiring film made of Cu having a thickness of 10 nm was formed on the barrier film made of TiN by the PVD method.
  • the PVD method was performed under conditions of a pressure of 0.1 Pa and a substrate temperature of 20 ° C.
  • a barrier film made of TiN having a thickness of 10 nm is formed by the PVD method, and a bias voltage is applied to the substrate on the surface of the barrier film made of TiN.
  • the same operation as in Example 1 was performed except that the operation of irradiating hydrogen plasma was not performed while applying.
  • Example 2 The same operation as in Example 1 was performed except that the operation of irradiating hydrogen plasma while applying a bias voltage to the surface of the barrier film made of TiN was not performed.
  • Test Example 1 The substrates on which the barrier film and the metal wiring film of Example 1 and Comparative Examples 1 and 2 were formed were each heated at 300 ° C. for 1 hour to evaluate the adhesion between the barrier film and the metal wiring film.
  • FIG. 5 shows photographs obtained by SEM observation of the surface of the metal wiring film before and after heating at 300 ° C. for 1 hour. If the adhesion between the barrier film and the metal wiring film is poor, the metal wiring film is agglomerated and rounded by surface tension due to heating.
  • Example 1 in which a barrier film was formed by ALD and irradiated with hydrogen plasma, Cl derived from ALD source gas TiCl 4 remaining on the surface of the barrier film was replaced with hydrogen ions or hydrogen.
  • the metal wiring film was not aggregated because it was removed by radicals, and the adhesion between the barrier film and the metal wiring film was good.
  • Comparative Example 2 in which the hydrogen plasma irradiation was not performed, it was found that the metal wiring film was agglomerated and the adhesion between the barrier film and the metal wiring film was poor. This is probably because Cl remained on the barrier film surface and the adhesion was poor.
  • Comparative Example 1 in which the barrier film was formed by the PVD method, pure metal was used as a raw material, and the adhesiveness was good as in Example 1, probably because there was no impurity such as TiCl 4 .
  • Example 2 After forming a barrier film made of TiN having a thickness of 10 nm by Cat-ALD method under the same conditions as in Example 1, and irradiating the surface of the barrier film made of TiN with hydrogen plasma while applying a bias voltage to the substrate Then, the film was transported (vacuum continuous transport) to a device for forming a metal wiring film without being exposed to the atmosphere, and a metal wiring film made of Cu having a thickness of 100 nm was formed on the barrier film made of TiN by the CVD method.
  • the CVD method uses a cupra select (Cu + 1 (hfac) (tmvs)) manufactured by Schmucker as a raw material gas, a raw material flow rate of 0.2 g / min, a carrier (argon) flow rate of 1000 sccm, a pressure of 200 Pa, and a substrate temperature of 180 ° C. It went on condition of.
  • Example 3 The same operation as in Example 2 was performed, except that the substrate bias value when the barrier film was irradiated with hydrogen plasma was changed to 500 W (power density 0.71 W / cm 2 ) instead of 200 W.
  • Comparative Example 3 A barrier film made of TiN having a thickness of 10 nm was formed by the Cat-ALD method under the same conditions as in Comparative Example 2, and then formed on the barrier film made of TiN by the CVD method under the same conditions as in Example 2. A metal wiring film made of 100 nm Cu was formed.
  • Test Example 2 For the substrates on which the barrier film and the metal wiring film of Examples 2 to 3 and Comparative Example 3 were formed, the barrier film and the metal wiring film were formed according to the plating adhesion test (tape test) defined in JIS H8504. The adhesion was evaluated. The photograph which observed the surface of the metal wiring film after peeling off a tape is shown in FIG.
  • Example 2 the metal wiring film was hardly peeled off, and the adhesion between the barrier film and the metal wiring film was good. Further, in Example 3, no peeling of the metal wiring film was observed, and the adhesion was better than that in Example 2. From this, it was found that the higher the substrate bias, the better the adhesion. This is because when hydrogen ions and hydrogen radicals gain kinetic energy from the bias voltage applied to the substrate and collide with the barrier film, they react with chlorine on the surface of the barrier film more efficiently, and are eliminated as HCl. it is conceivable that. On the other hand, in Comparative Example 3 in which the barrier film was not irradiated with hydrogen plasma, the metal wiring film was peeled off, and there was no adhesion between the barrier film and the metal wiring film.
  • Example 3 The same operation as in Example 3 was performed except that the substrate temperature at the time of irradiation with hydrogen plasma was set to 150 ° C., 180 ° C., 250 ° C., and 380 ° C., respectively. At 250 ° C., no peeling of the metal wiring film was observed as in Example 3. However, when the temperature was set to 150 ° C. or 380 ° C., compared with the case where the temperature was within the range of 180 to 350 ° C. Adhesion was slightly reduced.
  • the substrate bias values are 0 W (power density 0 W / cm 2 ), 150 W (power density 0.21 W / cm 2 ), 800 W (power density 1.13 W / cm 2 ), 1000 W (power density 1.42 W / cm), respectively.
  • cm 2 power density 0.21 W / cm 2
  • 800 W power density 1.13 W / cm 2
  • 1000 W power density 1.42 W / cm
  • the metal wiring film was peeled off. Further, the same operation as in Example 2 was performed except that the substrate bias value was changed using a ⁇ 200 mm silicon wafer instead of the ⁇ 300 mm silicon wafer. As in the case of ⁇ 300 mm, the power density was 0.25 to In the range of 1.5 W / cm 2 , the adhesion between the barrier film and the metal wiring film was particularly good.
  • the surface of the barrier film made of TiN was irradiated with hydrogen plasma while applying a bias voltage to the substrate.
  • the hydrogen plasma irradiation was performed under the same conditions as in Example 1.
  • Example 4 The same operation as in Example 4 was performed except that the operation of irradiating hydrogen plasma while applying a bias voltage to the surface of the barrier film made of TiN was not performed. The photograph which observed the cross section by SEM is shown in FIG.
  • Example 4 in which the barrier film was irradiated with hydrogen plasma while applying a bias voltage to the substrate, the adhesion between the barrier film and the metal wiring film was good, so that Cu was formed without forming voids. Was embedded.
  • Comparative Example 4 in which the operation of irradiating the barrier film with hydrogen plasma while applying a bias voltage to the substrate was not performed, the adhesion between the barrier film and the metal wiring film was poor, so the Cu film aggregated in the hole. There was a void.
  • the substrate temperature was set to 180 ° C. (FIG. 8A) when forming a metal wiring film made of Cu having a thickness of 200 nm on the barrier film made of TiN by the CVD method, 160 ° C. and 170 ° C., respectively.
  • the substrate temperature was set to 170 ° C. or 190 ° C. except that the temperature was set to 190 ° C. and 200 ° C. Since the adhesion between the barrier film and the metal wiring film was good, Cu was embedded without forming a void.
  • the temperature is 200 ° C.
  • a cross-sectional SEM observation is shown in FIG. 8B. As described above, Cu was not sufficiently embedded, and when the temperature was set to 160 ° C., impurities F and C were contained in the Cu film, which was not suitable for practical use as a wiring.

Abstract

A metal nitride film, which serves as a barrier film, is formed on a substrate having a hole or trench formed therein by a CVD process or an ALD process, and the surface of the metal nitride film is irradiated with a hydrogen plasma or a hydrogen radical while applying a bias voltage to the substrate side of the metal nitride film.

Description

バリア膜の形成方法及び金属配線膜の形成方法Barrier film formation method and metal wiring film formation method
　本発明は、バリア膜の形成方法及び金属配線膜の形成方法に関し、特に微細なトレンチまたはホール内に形成されるＣｕ膜等の金属配線膜の下地としてのバリア膜の形成方法及び金属配線膜の形成方法に関する。 The present invention relates to a method for forming a barrier film and a method for forming a metal wiring film, and in particular, a method for forming a barrier film as a base of a metal wiring film such as a Cu film formed in a fine trench or hole, and a metal wiring film It relates to a forming method.
　フラシュッメモリに代表される半導体メモリや大規模集積回路（ＬＳＩ）の高集積化に伴い、０．０５μｍ以下の金属相互配線は、重要な役割を持つ。アルミニウム（Ａｌ）は電気特性に優れ且つ安価なため金属相互配線に広く用いられているが、デバイス密度や配線長が増すにつれて限界に達する。すなわち、０．１８μｍ以下のデバイスでは配線遅延がデバイスの高速化を律速することが分かっている。それゆえ、次世代のデバイスの要求を満たす新しい金属相互配線が必要とされている。 With the high integration of semiconductor memories typified by flash memory and large-scale integrated circuits (LSIs), metal interconnections of 0.05 μm or less play an important role. Aluminum (Al) is widely used for metal interconnections because of its excellent electrical characteristics and low cost. However, the limit is reached as the device density and wiring length increase. That is, it has been found that in devices of 0.18 μm or less, the wiring delay determines the speeding up of the device. Therefore, there is a need for new metal interconnects that meet the demands of next generation devices.
　そして、銅（Ｃｕ）はＡｌの代わりとなる配線用金属として研究され、一部実用化されている。Ｃｕの抵抗率（１．６７×１０－６Ω・ｃｍ）は、Ａｌの抵抗率（２．６６×１０－６Ω・ｃｍ）と比較して、６０％程度と低いため、配線遅延が少なくデバイスを高速化できる。また、ＣｕはＡｌより重い元素であるためにエレクトロマイグレーションやストレスマイグレーションに対する耐性が強く、信頼性の高い配線を実現できる。 Copper (Cu) has been studied as a wiring metal instead of Al and has been partially put into practical use. The resistivity of Cu (1.67 × 10 −6 Ω · cm) is about 60% lower than that of Al (2.66 × 10 −6 Ω · cm), so there is less wiring delay. Speed up the device. In addition, since Cu is an element heavier than Al, it has high resistance to electromigration and stress migration, and can realize highly reliable wiring.
　Ｃｕ配線を形成する方法として、トレンチやホール等が形成されたウェハ等の基板上に、物理気相成長（Ｐｈｙｓｉｃａｌ　Ｖａｐｏｒ　Ｄｅｐｏｓｉｔｉｏｎ、ＰＶＤ）法により、Ｃｕがウエハ上に形成した絶縁膜に拡散することを抑制するための金属窒化物膜等のバリア膜を形成した後、電気めっき処理のためのシード膜を形成し、その後電気めっき（Ｅｌｅｃｔｒｏ　ｐｌａｔｉｎｇ）法によりトレンチやホール等を埋め込む方法が、一般的に用いられている。しかし、Ｃｕ配線の微細化によりウェハ等の中央部と端部との非対称性、あるいは、バリア膜やシード膜のオーバーハングが顕著になり、電気めっきの際にボイドが発生するという問題がある。具体的には、例えば、図１（ａ）及び（ｂ）に示すように、φ３２ｎｍのホールやトレンチが設けられている基板１０１上に形成されているバリア膜１０２上にＰＶＤ法によりシード膜１０３を形成すると、ホールやトレンチの上部がオーバーハング（Ａ部分）してホール等の開口部が狭まり、次いでメッキ工程によりホール等の内部をＣｕ膜１０４で埋め込む際に、メッキ液が内部に入り難くなると共に、Ｃｕ膜とバリア膜との密着性が良くないために、Ｃｕ膜が埋め込まれるにつれてＣｕ膜が吸いあがって、Ｃｕ膜中にボイド（Ｂ部分）が発生するという問題がある。また、図１（ｃ）及び（ｄ）に示すように、ホール等の側面にＰＶＤによりシード膜１０３が均一に対称的に形成できず（Ｃ部分）、このバリア膜の非対称性のために、次のメッキ工程において埋め込まれるＣｕ膜１０４中にボイド（Ｄ部分）が発生するという問題もある。 As a method of forming Cu wiring, Cu is diffused into an insulating film formed on a wafer by a physical vapor deposition (PVD) method on a substrate such as a wafer in which trenches and holes are formed. Generally, a method of forming a barrier film such as a metal nitride film for suppressing the deposition, forming a seed film for electroplating, and then embedding trenches or holes by an electroplating method is generally used. It is used for. However, the miniaturization of the Cu wiring makes the asymmetry between the central portion and the end portion of the wafer or the like, or the overhang of the barrier film or the seed film becomes remarkable, and there is a problem that voids are generated during electroplating. Specifically, for example, as shown in FIGS. 1A and 1B, a seed film 103 is formed on a barrier film 102 formed on a substrate 101 provided with a φ32 nm hole or trench by a PVD method. When the hole is formed, the upper part of the hole or trench is overhanged (part A) and the opening of the hole or the like is narrowed. Then, when the inside of the hole or the like is filled with the Cu film 104 by the plating process, the plating solution is difficult to enter. In addition, since the adhesion between the Cu film and the barrier film is not good, there is a problem that the Cu film is sucked up as the Cu film is buried, and voids (B portion) are generated in the Cu film. In addition, as shown in FIGS. 1C and 1D, the seed film 103 cannot be uniformly and symmetrically formed by PVD on the side surfaces of holes or the like (C portion), and due to the asymmetry of this barrier film, There is also a problem that voids (D portion) are generated in the Cu film 104 to be embedded in the next plating step.
　一方、化学気相成長（ｃｈｅｍｉｃａｌ　ｖａｐｏｒ　ｄｅｐｏｓｉｔｉｏｎ、ＣＶＤ）法やＡＬＤ（Ａｔｏｍｉｃ　Ｌａｙｅｒ　Ｄｅｐｏｓｉｔｉｏｎ：原子層蒸着）法は段差被覆性に優れることから、上記非対称性やオーバーハングの問題が無いため、配線の微細化に対応できると考えられる。 On the other hand, the chemical vapor deposition (CVD) method and the ALD (Atomic Layer Deposition) method are excellent in step coverage, so there is no problem of the above asymmetry and overhang. It is thought that it can cope with the conversion.
　しかしながら、ＣＶＤ法やＡＬＤ法によりバリア膜を形成すると、バリア膜上に形成されるＣｕ配線との密着性が不十分であるという問題がある。そして、このような問題は、配線としてＣｕを用いた場合に限らず、Ｃｕ以外の金属配線においても、同様に存在する。このような問題は、バリア膜上にＰＶＤ法によりＣｕシード膜を形成した後に電気めっきによりＣｕ配線膜を形成する現在主流の方法においても存在するが、バリア膜上にＣＶＤ法でＣｕ配線を直接形成した場合に、より顕著である。 However, when the barrier film is formed by the CVD method or the ALD method, there is a problem that the adhesion with the Cu wiring formed on the barrier film is insufficient. Such a problem is not limited to the case where Cu is used as the wiring, but also exists in metal wiring other than Cu. Such a problem also exists in the current mainstream method of forming a Cu wiring film by electroplating after forming a Cu seed film on the barrier film by the PVD method, but the Cu wiring is directly formed on the barrier film by the CVD method. It is more noticeable when formed.
　なお、特許文献１では、金属窒化物膜を積層する際に水素ガス及びシラン系ガスのプラズマを照射する技術が開示されているが、水素を単独で用いるものではなく、また、金属窒化物膜とその上に形成される金属配線膜との密着性に注目したものでもない。 Patent Document 1 discloses a technique of irradiating plasma of hydrogen gas and silane-based gas when laminating metal nitride films, but hydrogen is not used alone, and metal nitride films are not used. Further, it does not pay attention to the adhesiveness between the film and the metal wiring film formed thereon.
特開２０００－１９５８２０号公報JP 2000-195820 A
　本発明の課題は、上述の従来技術の問題点を解決することにあり、金属配線膜との密着性に優れたバリア膜の形成方法及び金属配線膜の形成方法を提供することにある。 An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a method for forming a barrier film and a method for forming a metal wiring film that are excellent in adhesion to the metal wiring film.
　上記課題を解決する本発明のバリア膜の形成方法は、ホールまたはトレンチが形成されている基板上にバリア膜となる金属窒化物膜をＣＶＤ法またはＡＬＤ法により形成し、前記基板側にバイアス電圧を印加しながら前記金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射することを特徴とする。 In the method for forming a barrier film of the present invention that solves the above-described problem, a metal nitride film serving as a barrier film is formed by a CVD method or an ALD method on a substrate in which holes or trenches are formed, and a bias voltage is applied to the substrate side. The surface of the metal nitride film is irradiated with hydrogen plasma or hydrogen radicals while applying.
　また、前記基板側に印加するバイアス電圧は、電力密度が０．２５～１．５Ｗ／ｃｍ２となるように電力を供給することにより前記基板側に印加されるものであることが好ましい。 The bias voltage applied to the substrate side is preferably applied to the substrate side by supplying power so that the power density is 0.25 to 1.5 W / cm 2 .
　そして、前記金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射するときの前記基板の温度は、１８０℃～３５０℃であることが好ましい。 The temperature of the substrate when the surface of the metal nitride film is irradiated with hydrogen plasma or hydrogen radicals is preferably 180 ° C. to 350 ° C.
　また、前記金属窒化物膜は、窒化チタン、窒化タングステン、窒化タンタル、窒化ジルコニウムまたは窒化バナジウムからなる膜であってもよい。 The metal nitride film may be a film made of titanium nitride, tungsten nitride, tantalum nitride, zirconium nitride, or vanadium nitride.
　本発明の金属配線膜の形成方法は、上記バリア膜の形成方法により形成されたホールまたはトレンチ内のバリア膜上に、ＣＶＤ法またはＰＶＤ法により金属配線膜を形成することを特徴とする。 The method for forming a metal wiring film according to the present invention is characterized in that a metal wiring film is formed by a CVD method or a PVD method on a barrier film in a hole or a trench formed by the barrier film forming method.
　また、前記金属配線膜は、銅、アルミニウムまたはタングステンからなる膜であってもよい。 Further, the metal wiring film may be a film made of copper, aluminum or tungsten.
　そして、前記バリア膜上に前記金属配線膜を形成するときの基板の温度は、１７０℃～１９０℃であることが好ましい。 The substrate temperature when forming the metal wiring film on the barrier film is preferably 170 ° C. to 190 ° C.
　また、本発明の金属配線膜の形成方法は、ホールまたはトレンチが形成されている基板上にバリア膜となる金属窒化物膜をＣＶＤ法またはＡＬＤ法により形成した後、前記基板側に電力密度が０．２５～１．５Ｗ／ｃｍ２となるように電力を供給することにより基板側にバイアス電圧を印加しながら前記金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射することによりバリア膜を形成し、その後ホールまたはトレンチ内に形成されたバリア膜上に、ＣＶＤ法またはＰＶＤ法により金属配線膜を形成することを特徴とする。 In the metal wiring film forming method of the present invention, a metal nitride film serving as a barrier film is formed on a substrate on which holes or trenches are formed by a CVD method or an ALD method. The barrier film is formed by irradiating the surface of the metal nitride film with hydrogen plasma or hydrogen radicals while applying a bias voltage to the substrate side by supplying electric power so as to be 0.25 to 1.5 W / cm 2. A metal wiring film is formed by CVD or PVD on the barrier film formed in the hole or trench after formation.
　本発明によれば、金属配線膜との密着性に優れたバリア膜を形成することができ、このバリア膜上に形成された金属配線膜の剥がれを抑制できるという効果を奏する。 According to the present invention, it is possible to form a barrier film having excellent adhesion to the metal wiring film, and to suppress the peeling of the metal wiring film formed on the barrier film.
従来技術の場合のボイド発生を示す模式図である。It is a schematic diagram which shows the void generation | occurrence | production in the case of a prior art. 水素プラズマ処理装置の一構成例を示す模式図である。It is a schematic diagram which shows one structural example of a hydrogen plasma processing apparatus. 水素ラジカル処理装置の一構成例を示す模式図である。It is a schematic diagram which shows one structural example of a hydrogen radical processing apparatus. 本発明で形成されるバリア膜及び金属配線膜を示す基板の断面図である。It is sectional drawing of the board | substrate which shows the barrier film and metal wiring film which are formed by this invention. 試験例１の結果を示す写真である。6 is a photograph showing the results of Test Example 1. 試験例２の結果を示す写真である。6 is a photograph showing the results of Test Example 2. 実施例４及び比較例４における基板の断面を観察した写真である。It is the photograph which observed the cross section of the board | substrate in Example 4 and Comparative Example 4. FIG. １８０℃及び２００℃でＣｕを成膜したときの基板の断面を観察した写真である。It is the photograph which observed the cross section of the board | substrate when Cu was formed into a film at 180 degreeC and 200 degreeC.
　本発明のバリア膜の形成方法は、ホールまたはトレンチが形成されている基板上にバリア膜となる金属窒化物膜をＣＶＤ法またはＡＬＤ法により形成し、基板側にバイアス電圧を印加しながら金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射するものであり、本発明の金属配線膜の形成方法は、このバリア膜上にさらに金属配線膜を形成するものである。 According to the method for forming a barrier film of the present invention, a metal nitride film to be a barrier film is formed by CVD or ALD on a substrate in which holes or trenches are formed, and metal nitridation is performed while applying a bias voltage to the substrate side. The surface of the material film is irradiated with hydrogen plasma or hydrogen radicals, and the metal wiring film forming method of the present invention further forms a metal wiring film on the barrier film.
　すなわち、まず、ウェハー等の基板上のホールまたはトレンチ等の内部にバリア膜となる金属窒化物膜をＣＶＤ法またはＡＬＤ法により形成する。なお、ホールやトレンチの大きさは特に限定されない。 That is, first, a metal nitride film serving as a barrier film is formed by CVD or ALD in a hole or trench on a substrate such as a wafer. The size of the hole or trench is not particularly limited.
　ＣＶＤ法またはＡＬＤ法により形成する金属窒化物膜としては、ＴｉＮ、ＴａＮ、ＷＮ、ＺｒＮ、ＶＮ等が挙げられる。なお、ＣＶＤ（ｃｈｅｍｉｃａｌ　ｖａｐｏｒ　ｄｅｐｏｓｉｔｉｏｎ）法とは、原料ガスを基板上に流しこの原料ガスの反応生成物を基板上に蒸着させる方法をいい、ＡＬＤ（Ａｔｏｍｉｃ　Ｌａｙｅｒ　Ｄｅｐｏｓｉｔｉｏｎ：原子層蒸着）法とは、２つ以上の原料ガスを交互に基板表面に供給し反応させることにより基板上で成膜を行うものである。ＡＬＤ法やＣＶＤ法の原料ガスとしては、ＴｉＮ膜であれば、例えばＴｉＣｌ４ガス、ＮＨ３ガス、Ｈ２ガスが挙げられる。また、ＴａＮ膜の原料ガスとしては、ＴａＣｌ５、ＴａＦ５、ＴａＩ５、ＴａＢｒ５や、ＴＢＴＤＥＴ（ｔｅｒｔ－ブチルイミドトリス（ジメチルアミド）タンタル）、ＴＡＩＭＡＴＡ（ｔｅｒｔ－アミルイミドトリス（ジメチルアミド）タンタル）、ＰＤＭＡＴ（ペンタジメチルアミノタンタル）等の有機金属化合物、ＮＨ３ガス、Ｈ２ガスが挙げられる。なお、例えば触媒を用いたＣＶＤ法（Ｃａｔ－ＣＶＤ法）やＡＬＤ法（Ｃａｔ－ＡＬＤ法）を用いることにより、効率よく金属窒化物膜を形成することができる。 Examples of the metal nitride film formed by the CVD method or the ALD method include TiN, TaN, WN, ZrN, and VN. The CVD (Chemical Vapor Deposition) method refers to a method in which a raw material gas is flowed over a substrate and a reaction product of the raw material gas is deposited on the substrate. ALD (Atomic Layer Deposition) method is Two or more source gases are alternately supplied to the substrate surface and reacted to form a film on the substrate. As a source gas for the ALD method or the CVD method, for example, TiCl 4 gas, NH 3 gas, and H 2 gas may be used in the case of a TiN film. As the source gas for the TaN film, TaCl 5 , TaF 5 , TaI 5 , TaBr 5 , TBTDET (tert-butylimidotris (dimethylamido) tantalum), TAIMATA (tert-amylimidotris (dimethylamido) tantalum) And organometallic compounds such as PDMAT (pentadimethylamino tantalum), NH 3 gas, and H 2 gas. For example, a metal nitride film can be efficiently formed by using a CVD method (Cat-CVD method) or an ALD method (Cat-ALD method) using a catalyst.
　このようにして金属窒化物膜を形成した後に、基板にバイアス電圧を印加しながら金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射する。このように基板にバイアス電圧を印加しながら金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射することにより、後述する実施例に示すように、金属窒化物膜からなるバリア膜とこのバリア膜上に形成される金属配線膜との密着性が良好になる。これは、基板にバイアス電圧を印加しながら金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射することにより、金属窒化物膜の原料に含まれる塩素、フッ素、炭素などの不純物が、水素イオンや水素ラジカルと反応して気体となって金属窒化物膜表面から除去されるため、密着性が良好になると推測される。 After forming the metal nitride film in this manner, the surface of the metal nitride film is irradiated with hydrogen plasma or hydrogen radicals while applying a bias voltage to the substrate. By irradiating the surface of the metal nitride film with hydrogen plasma or hydrogen radicals while applying a bias voltage to the substrate in this way, a barrier film made of a metal nitride film and the barrier film are formed as shown in Examples described later. Adhesion with the metal wiring film formed on the top is improved. This is because the surface of the metal nitride film is irradiated with hydrogen plasma or hydrogen radicals while applying a bias voltage to the substrate, so that impurities such as chlorine, fluorine, and carbon contained in the material of the metal nitride film become hydrogen ions. Since it reacts with hydrogen radicals to form a gas and is removed from the surface of the metal nitride film, it is assumed that the adhesion is improved.
　ここで、従来技術のように、基板にバイアス電圧を印加しながら金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射する操作を行わない場合は、ＣＶＤ法やＡＬＤ法により形成された金属窒化物膜の原料由来の塩素、フッ素、炭素などの不純物がバリア膜上に残留することにより、ＣＭＰプロセスでの膜剥離が起こる。また、高ビア抵抗、エレクトロマイグレーション耐性が不十分になることから生じるデバイスの動作不良が生じる。しかしながら、本発明においては、塩素、フッ素、炭素などの不純物が除去されているため、密着性が良好になり、ＣＭＰプロセスでの膜剥離が抑制できる。また、高ビア抵抗、エレクトロマイグレーション耐性が不十分になることから生じるデバイスの動作不良が抑制できる。なお、ＰＶＤ法により金属窒化物膜を形成する場合は、純金属を原料として使用するため、ＣＶＤ法やＡＬＤ法の場合に生じる金属配線膜との密着性が不十分になるという問題は小さい。 Here, as in the prior art, when the operation of irradiating the surface of the metal nitride film with hydrogen plasma or hydrogen radical is not performed while applying a bias voltage to the substrate, the metal nitridation formed by the CVD method or the ALD method is performed. When impurities such as chlorine, fluorine, and carbon derived from the material of the material film remain on the barrier film, film peeling occurs in the CMP process. In addition, device malfunction occurs due to insufficient high via resistance and electromigration resistance. However, in the present invention, since impurities such as chlorine, fluorine, and carbon are removed, adhesion is improved and film peeling in the CMP process can be suppressed. In addition, device malfunction caused by insufficient high via resistance and electromigration resistance can be suppressed. In the case of forming a metal nitride film by the PVD method, pure metal is used as a raw material, so that the problem of insufficient adhesion to the metal wiring film caused by the CVD method or the ALD method is small.
　このような基板にバイアス電圧を印加しながら金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射する操作を行う装置の構成例を図２（ａ）及び（ｂ）に示す。 2A and 2B show a configuration example of an apparatus for performing an operation of irradiating the surface of the metal nitride film with hydrogen plasma or hydrogen radical while applying a bias voltage to such a substrate.
　水素プラズマを照射する水素プラズマ処理装置の一構成を示す模式図である図２（ａ）によれば、水素プラズマ処理装置２０は、ポンプ等の真空排気手段２１を備えた真空チャンバ２２を有する。そして、真空チャンバ２２内には、上面に石英板２３が設けられた基板支持台２４が設置されており、この基板支持台２４（ひいては石英板２３）上にバリア膜（図示なし）が形成された基板Ｓが載置される。この石英板２３は、基板支持台２４が水素プラズマによって削られるのを防止するために設けられる。また、真空チャンバ２２の天井部または側壁には、真空チャンバ２２内に水素ガスを導入する水素ガス導入手段（図示なし）が設けられている。また、真空チャンバ２２の天井部外側には、基板Ｓを加熱するランプヒーター等の加熱手段２５が設けられている。そして、真空チャンバ２２の天井部には加熱手段２５からの熱を透過せしめる石英窓２６が設けられている。さらに、基板支持台２４には、基板支持台２４（ひいては基板Ｓ）にバイアス電圧を印加するための高周波電源２７が接続されている。そして、この高周波電源２７は、真空チャンバ２２の上方にプラズマＰを発生させるように構成されている。 According to FIG. 2 (a), which is a schematic diagram showing one configuration of a hydrogen plasma processing apparatus for irradiating hydrogen plasma, the hydrogen plasma processing apparatus 20 has a vacuum chamber 22 provided with a vacuum exhaust means 21 such as a pump. A substrate support 24 having a quartz plate 23 provided on the upper surface is installed in the vacuum chamber 22, and a barrier film (not shown) is formed on the substrate support 24 (and thus the quartz plate 23). A substrate S is placed. The quartz plate 23 is provided to prevent the substrate support 24 from being scraped by hydrogen plasma. Further, hydrogen gas introduction means (not shown) for introducing hydrogen gas into the vacuum chamber 22 is provided on the ceiling or side wall of the vacuum chamber 22. A heating means 25 such as a lamp heater for heating the substrate S is provided outside the ceiling portion of the vacuum chamber 22. A quartz window 26 that allows heat from the heating means 25 to pass therethrough is provided at the ceiling of the vacuum chamber 22. Further, the substrate support 24 is connected to a high frequency power source 27 for applying a bias voltage to the substrate support 24 (and thus the substrate S). The high frequency power supply 27 is configured to generate plasma P above the vacuum chamber 22.
　このような水素プラズマ処理装置２０で水素プラズマを照射するには、まず、基板支持台２４上に金属窒化物膜からなるバリア膜が形成された基板Ｓを載置する。そして、加熱手段２５により基板Ｓを所定温度に加熱すると共に高周波電源２７から基板Ｓに所定電圧を印加する。また、真空排気手段２１により真空チャンバ２２内を所定の真空度まで排気する。そして、水素ガス導入手段から水素ガスを真空チャンバ２２内に導入することにより、水素プラズマを発生させ、この水素プラズマを基板Ｓ上に形成された金属窒化物膜からなるバリア膜に照射する。 In order to irradiate hydrogen plasma with such a hydrogen plasma processing apparatus 20, first, a substrate S on which a barrier film made of a metal nitride film is formed is placed on the substrate support 24. Then, the substrate S is heated to a predetermined temperature by the heating means 25 and a predetermined voltage is applied to the substrate S from the high frequency power source 27. Further, the inside of the vacuum chamber 22 is evacuated to a predetermined degree of vacuum by the evacuation means 21. Then, hydrogen gas is introduced into the vacuum chamber 22 from the hydrogen gas introducing means, thereby generating hydrogen plasma, and irradiating the hydrogen plasma to the barrier film made of the metal nitride film formed on the substrate S.
　また、水素プラズマを照射する水素プラズマ処理装置の別の構成を示す模式図である図２（ｂ）によれば、水素プラズマ処理装置４０は、ポンプ等の真空排気手段４１を備えた真空チャンバ４２を有する。そして、真空チャンバ４２内には、上面にＡｌＮヒーター等の加熱手段４５が設けられた基板支持台４４が設置されており、この加熱手段４５上にバリア膜（図示なし）が形成された基板Ｓが載置される。また、加熱手段４５上面の基板Ｓが載置されない端縁部には、石英板４３が設けられている。この石英板４３は、基板支持台４４が水素プラズマによって削られるのを防止するために設けられる。また、真空チャンバ４２の天井部または側壁には、真空チャンバ４２内に水素ガスを導入する水素ガス導入手段（図示なし）が設けられている。そして、基板支持台４４には、基板支持台２４（ひいては基板Ｓ）にバイアス電圧を印加するための高周波電源４７が接続されている。また、真空チャンバ４２の側面の外側には、高周波電源４８に接続されたアンテナコイル４９が設けられており、アンテナコイル４９に高周波を印加して高密度のプラズマ放電を行い、真空チャンバ２２の上方にプラズマＰを発生させるように構成されている。さらに、真空チャンバ４２の内面には、真空チャンバ４２の内壁の汚れを防止する着脱可能なアルミナ等の防着板５０が設けられている。 Further, according to FIG. 2B, which is a schematic diagram showing another configuration of the hydrogen plasma processing apparatus for irradiating the hydrogen plasma, the hydrogen plasma processing apparatus 40 includes a vacuum chamber 42 provided with a vacuum exhaust means 41 such as a pump. Have In the vacuum chamber 42, a substrate support table 44 having an upper surface provided with heating means 45 such as an AlN heater is installed, and the substrate S on which a barrier film (not shown) is formed on the heating means 45. Is placed. In addition, a quartz plate 43 is provided at the edge of the upper surface of the heating unit 45 where the substrate S is not placed. The quartz plate 43 is provided to prevent the substrate support 44 from being scraped by hydrogen plasma. Further, hydrogen gas introduction means (not shown) for introducing hydrogen gas into the vacuum chamber 42 is provided on the ceiling or side wall of the vacuum chamber 42. The substrate support 44 is connected to a high frequency power supply 47 for applying a bias voltage to the substrate support 24 (and thus the substrate S). Further, an antenna coil 49 connected to a high frequency power supply 48 is provided outside the side surface of the vacuum chamber 42, and high frequency is applied to the antenna coil 49 to perform high-density plasma discharge. The plasma P is generated. Further, an inner surface of the vacuum chamber 42 is provided with a removable attachment plate 50 such as detachable alumina that prevents the inner wall of the vacuum chamber 42 from being soiled.
　このような水素プラズマ処理装置４０で水素プラズマを照射するには、まず、基板支持台４４上に設けられた加熱手段４５上に金属窒化物膜からなるバリア膜が形成された基板Ｓを載置する。そして、加熱手段４５により基板Ｓを所定温度に加熱すると共に高周波電源４７から基板Ｓに所定電圧を印加する。また、真空排気手段４１により真空チャンバ４２内を所定の真空度まで排気する。そして、アンテナコイル４９に高周波電源４８から電圧を印加させ、水素ガス導入手段から水素ガスを真空チャンバ４２内に導入することにより、高密度の水素プラズマを発生させ、この水素プラズマを基板Ｓ上に形成された金属窒化物膜からなるバリア膜に照射する。 In order to irradiate hydrogen plasma with such a hydrogen plasma processing apparatus 40, first, a substrate S on which a barrier film made of a metal nitride film is formed is placed on a heating means 45 provided on a substrate support base 44. To do. Then, the substrate S is heated to a predetermined temperature by the heating means 45 and a predetermined voltage is applied to the substrate S from the high frequency power source 47. Further, the inside of the vacuum chamber 42 is evacuated to a predetermined degree of vacuum by the evacuation means 41. Then, a voltage is applied to the antenna coil 49 from the high frequency power supply 48 and hydrogen gas is introduced into the vacuum chamber 42 from the hydrogen gas introducing means, thereby generating a high-density hydrogen plasma. The barrier film made of the formed metal nitride film is irradiated.
　次に、触媒によって水素ラジカルを発生させて照射する水素ラジカル処理装置６０の一構成の模式図を図３に示す。図３によれば、水素ラジカル処理装置６０は、ポンプ等の真空排気手段６１を備えた真空チャンバ６２を有する。そして、真空チャンバ６２内には、上面にヒーター等の加熱手段６５が設けられた基板支持台６４が設けられており、この加熱手段６５上にバリア膜（図示なし）が形成された基板Ｓが載置される。また、真空チャンバ６２の天井部には、真空チャンバ６２内に水素ガスやキャリアガス（例えばアルゴン等）を導入するシャワープレート等の水素ガス導入手段６６が設けられている。また、基板支持台６４には、基板支持台６４（ひいては基板Ｓ）にバイアス電圧を印加するための高周波電源６７が設けられている。そして、真空チャンバ６２の上方には、水素ガス導入手段６６と対向して、導入された水素ガスを接触させるようにタングステン等からなる触媒線７０が設けられている。この触媒線７０によって、基板支持台６４（ひいては基板Ｓ）と水素ガス導入手段６６との間にラジカルを発生させるように構成されている。なお、触媒線７０は、触媒線７０が加熱されるように通電可能になっている。 Next, FIG. 3 shows a schematic diagram of one configuration of a hydrogen radical processing apparatus 60 that generates and irradiates hydrogen radicals with a catalyst. According to FIG. 3, the hydrogen radical processing apparatus 60 has a vacuum chamber 62 provided with a vacuum exhaust means 61 such as a pump. In the vacuum chamber 62, a substrate support base 64 having a heating means 65 such as a heater provided on the upper surface is provided. A substrate S on which a barrier film (not shown) is formed on the heating means 65 is provided. Placed. A hydrogen gas introducing means 66 such as a shower plate for introducing hydrogen gas or carrier gas (for example, argon) into the vacuum chamber 62 is provided at the ceiling of the vacuum chamber 62. Further, the substrate support base 64 is provided with a high frequency power supply 67 for applying a bias voltage to the substrate support base 64 (and consequently the substrate S). A catalyst wire 70 made of tungsten or the like is provided above the vacuum chamber 62 so as to face the hydrogen gas introduction means 66 so as to contact the introduced hydrogen gas. The catalyst wire 70 is configured to generate radicals between the substrate support base 64 (and consequently the substrate S) and the hydrogen gas introducing means 66. The catalyst wire 70 can be energized so that the catalyst wire 70 is heated.
　このような水素ラジカル処理装置６０で水素ラジカルを照射するには、まず、基板支持台６４上に設けられた加熱手段６５上に金属窒化物膜からなるバリア膜が形成された基板Ｓを載置する。そして、加熱手段６５により基板Ｓを所定温度に加熱すると共に高周波電源６７から基板Ｓに所定電圧を印加する。また、真空排気手段６１により真空チャンバ６２内を所定の真空度まで排気すると共に、触媒線７０に通電して触媒線７０を所定温度に加熱する。そして、水素ガス導入手段６６から水素ガスを真空チャンバ６２内に導入し、水素ガスを触媒線７０と接触させることにより水素ラジカルを発生させ、この水素ラジカルを基板Ｓ上に形成された金属窒化物膜からなるバリア膜に照射する。なお、真空チャンバ６２内等の不要なガスを除去するために、水素ガスを真空チャンバ６２内に導入する前に、アルゴン、ヘリウム等の希ガスや、窒素ガス等の不活性ガスを導入するようにしてもよい。 In order to irradiate hydrogen radicals with such a hydrogen radical processing apparatus 60, first, a substrate S on which a barrier film made of a metal nitride film is formed is placed on a heating means 65 provided on a substrate support base 64. To do. Then, the substrate S is heated to a predetermined temperature by the heating means 65 and a predetermined voltage is applied to the substrate S from the high frequency power source 67. Further, the inside of the vacuum chamber 62 is evacuated to a predetermined degree of vacuum by the evacuating means 61, and the catalyst line 70 is energized to heat the catalyst line 70 to a predetermined temperature. Then, hydrogen gas is introduced into the vacuum chamber 62 from the hydrogen gas introducing means 66, hydrogen radicals are generated by bringing the hydrogen gas into contact with the catalyst wire 70, and the hydrogen radicals are formed on the substrate S. Irradiate a barrier film made of a film. In order to remove unnecessary gas in the vacuum chamber 62 or the like, a rare gas such as argon or helium or an inert gas such as nitrogen gas is introduced before the hydrogen gas is introduced into the vacuum chamber 62. It may be.
　ここで、これらの水素プラズマ処理装置２０及び４０並びに水素ラジカル処理装置６０は、供給するガスを調整するための手段を設けることにより金属窒化物膜を形成するＣＶＤ装置やＡＬＤ装置としても使用できるため、金属窒化物膜の形成と、水素プラズマや水素ラジカルの照射を同一の装置で行うことができる。例えば、ＡＬＤ装置の場合、第１の原料ガスを供給する第１の原料ガス供給手段と第２の原料ガスを供給する第２の原料ガス供給手段とを真空チャンバの天井部または側壁に設けた装置とし、基板Ｓを基板支持台上に載置して、第１の原料ガス及び第２の原料ガスを交互に真空チャンバに導入することにより、ＡＬＤ法により基板上に金属窒化物膜を形成することができる。また、図２（ｂ）に示すように、真空チャンバの内面に真空チャンバの内壁の汚れを防止するための防着板を設けたＣＶＤ装置やＡＬＤ装置とすれば、ＣＶＤ法やＡＬＤ法による真空チャンバ壁面の汚れを抑制することができる。 Here, the hydrogen plasma processing apparatuses 20 and 40 and the hydrogen radical processing apparatus 60 can be used as a CVD apparatus or an ALD apparatus for forming a metal nitride film by providing means for adjusting the gas to be supplied. The formation of the metal nitride film and the irradiation with hydrogen plasma or hydrogen radical can be performed with the same apparatus. For example, in the case of an ALD apparatus, a first source gas supply unit that supplies a first source gas and a second source gas supply unit that supplies a second source gas are provided on the ceiling or side wall of the vacuum chamber. As a device, a substrate S is placed on a substrate support, and a first source gas and a second source gas are alternately introduced into a vacuum chamber, thereby forming a metal nitride film on the substrate by the ALD method. can do. In addition, as shown in FIG. 2B, if a CVD apparatus or ALD apparatus is provided with a deposition plate for preventing contamination of the inner wall of the vacuum chamber on the inner surface of the vacuum chamber, a vacuum by CVD or ALD is used. Contamination of the chamber wall surface can be suppressed.
　水素プラズマ及び水素ラジカルを基板に照射する具体的な条件は特に限定されないが、例えば、ＲＦ電源１３．５６ＭＨｚを用いて水素ガスをプラズマ化することにより、水素イオンや水素ラジカルを発生させればよい。具体的な処理条件例は、水素：１００～４００ｓｃｃｍ、アルゴン：０～２００ｓｃｃｍ、圧力：１～１００Ｐａ、照射時間：１０～１００秒程度である。また、水素イオンや水素ラジカルと金属窒化物膜との反応性を促進するため、基板Ｓの温度は、１８０℃以上が好ましく、例えば１８０℃～３５０℃である。 Specific conditions for irradiating the substrate with hydrogen plasma and hydrogen radicals are not particularly limited. For example, hydrogen ions or hydrogen radicals may be generated by converting hydrogen gas into plasma using an RF power source of 13.56 MHz. . Specific processing condition examples are hydrogen: 100 to 400 sccm, argon: 0 to 200 sccm, pressure: 1 to 100 Pa, and irradiation time: about 10 to 100 seconds. Further, in order to promote the reactivity between hydrogen ions or hydrogen radicals and the metal nitride film, the temperature of the substrate S is preferably 180 ° C. or higher, for example, 180 ° C. to 350 ° C.
　なお、上述したようにＣＶＤ法やＡＬＤ法で金属窒化物膜を形成してバリア膜を完成させた後、その最表面のみに基板にバイアス電圧を印加しながら水素プラズマまたは水素ラジカルを照射するようにしてもよいが、ＡＬＤ法で金属窒化物膜を形成している最中の一層を形成する毎に、基板にバイアス電圧を印加しながら水素プラズマまたは水素ラジカルを照射するようにしてもよい。すなわち、２つ以上の原料ガスを基板へ順に供給した後に水素プラズマまたは水素ラジカルを照射するという操作を繰り返すようにしてもよい。 As described above, after the metal nitride film is formed by CVD or ALD to complete the barrier film, only the outermost surface is irradiated with hydrogen plasma or hydrogen radicals while applying a bias voltage to the substrate. However, each time one layer is formed during the formation of the metal nitride film by the ALD method, hydrogen plasma or hydrogen radicals may be irradiated while applying a bias voltage to the substrate. That is, the operation of irradiating with hydrogen plasma or hydrogen radicals after sequentially supplying two or more source gases to the substrate may be repeated.
　金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射するときに基板に印加するバイアス電圧は、電力密度が０．２５～１．５Ｗ／ｃｍ２となるように基板に電力を供給することにより印加されるものとする、すなわち、電力密度が０．２５～１．５Ｗ／ｃｍ２となるように電力を供給することにより基板側にバイアス電圧を印加すると、特にバリア膜と金属配線膜との密着性が顕著に優れたものとなる。０．２５Ｗ／ｃｍ２未満では、密着性の向上が不十分であり、また、１．５Ｗ／ｃｍ２を超えると金属窒化物膜に水素が打ち込まれてしまう傾向があるため好ましくない。ここで、電力密度とは、基板に供給する電力を基板面積で割った値である。例えば直径３００ｍｍのウェハーを基板として使用した場合、基板に供給する電力を例えば２００Ｗ～１０００Ｗ程度とすればよい。なお、バイアス電圧は水素プラズマにより生じた水素イオンを基板側に引き込むために印加するもので、基板側に印加する必要がある。 The bias voltage applied to the substrate when the surface of the metal nitride film is irradiated with hydrogen plasma or hydrogen radicals is obtained by supplying power to the substrate so that the power density is 0.25 to 1.5 W / cm 2. When a bias voltage is applied to the substrate side by supplying power so that the power density is 0.25 to 1.5 W / cm 2 , particularly between the barrier film and the metal wiring film. The adhesiveness is remarkably excellent. If it is less than 0.25 W / cm 2 , the improvement in adhesion is insufficient, and if it exceeds 1.5 W / cm 2 , hydrogen tends to be implanted into the metal nitride film, which is not preferable. Here, the power density is a value obtained by dividing the power supplied to the substrate by the substrate area. For example, when a wafer having a diameter of 300 mm is used as the substrate, the power supplied to the substrate may be about 200 W to 1000 W, for example. The bias voltage is applied in order to draw hydrogen ions generated by the hydrogen plasma to the substrate side, and must be applied to the substrate side.
　また、水素プラズマや水素ラジカルを照射するための原料ガスは水素ガスのみにする必要があり、例えば特許文献１のように、水素ガスに加えてシラン系ガスや窒化水素ガスも用いると、本発明の密着性が良好になるという効果は得られない。また、特許文献１のように、水素ガスに加えてシラン系ガスを用いると、シラン系ガスがプラズマにより分解して、高抵抗なＳｉ膜が堆積してしまう場合がある。そして、窒化水素ガスを用いると、金属窒化膜が窒素リッチになり、高抵抗化してしまう場合がある。さらに、シラン系ガス等は無害化するための除害設備が必要であるという問題がある。 Further, the source gas for irradiating the hydrogen plasma or the hydrogen radical needs to be only hydrogen gas. For example, as in Patent Document 1, if a silane-based gas or a hydrogen nitride gas is used in addition to the hydrogen gas, the present invention is used. The effect of improving the adhesiveness is not obtained. Further, as in Patent Document 1, when a silane-based gas is used in addition to hydrogen gas, the silane-based gas may be decomposed by plasma and a high-resistance Si film may be deposited. When the hydrogen nitride gas is used, the metal nitride film becomes rich in nitrogen and may increase in resistance. Furthermore, there is a problem that a detoxification facility for detoxifying silane-based gas and the like is necessary.
　上記したように、水素プラズマまたは水素ラジカルを照射して、バリア膜を形成した後、バリア膜上に金属配線膜を形成する。金属配線膜の金属は特に限定されず、例えば、Ｃｕ、Ａｌ、Ｗが挙げられるが、微細化の点で、Ｃｕが好ましい。 As described above, after irradiating hydrogen plasma or hydrogen radicals to form a barrier film, a metal wiring film is formed on the barrier film. The metal of the metal wiring film is not particularly limited, and examples thereof include Cu, Al, and W. From the viewpoint of miniaturization, Cu is preferable.
　金属配線膜を形成する方法も特に限定されず、例えば、ＣＶＤ法、ＰＶＤ法、めっき法を用いればよいが、微細化の点からＣＶＤ法が好ましい。ＣＶＤ法ではＣｕを含んだ有機金属化合物を原料として用い、これを熱あるいはプラズマ等により分解して膜を形成する。用いられる有機金属化合物としては、ＳＣＨＵＭＡＣＨＥＲ（シュマッカー）社製のキュプラセレクト（Ｃｕｐｒａ　Ｓｅｌｅｃｔ、Ｃｕ＋１（ｈｆａｃ）（ｔｍｖｓ））、Ｃｕ（ＳＯＰＤ）２、Ｃｕ（ｅｄｍｏｄ）２、Ｃｕ（ｉｂｐｍ）２等が挙げられる。なお、ｈｆａｃはヘキサフルオロアセチルアセトネートアニオン、ｔｍｖｓはトリメチルビニルシラン、ＳＯＰＤは２，６－ジメチル－２－（トリメチルシリルオキシ）－３，５－ヘプタンジオナト、ｅｄｍｏｄはエチルジメチルオクタンジオナート、ｉｂｐｍはイソブチリルピバロイルメタネートの省略形であり、分子中にフッ素、塩素、炭素等を含む。 A method for forming the metal wiring film is not particularly limited, and for example, a CVD method, a PVD method, or a plating method may be used. From the viewpoint of miniaturization, the CVD method is preferable. In the CVD method, an organometallic compound containing Cu is used as a raw material, which is decomposed by heat or plasma to form a film. Examples of the organometallic compound used include cupra select (Cupra Select, Cu +1 (hfac) (tmvs)), Cu (SOPD) 2 , Cu (edmod) 2 , and Cu (ibpm) 2 manufactured by SCHUMAHER. Can be mentioned. Here, hfac is a hexafluoroacetylacetonate anion, tmvs is trimethylvinylsilane, SOPD is 2,6-dimethyl-2- (trimethylsilyloxy) -3,5-heptanedionate, edmod is ethyldimethyloctanedionate, and ibpm is isobutyrylpirate. It is an abbreviation for valoylmethanate and contains fluorine, chlorine, carbon, etc. in the molecule.
　また、基板の温度は、金属配線膜としてＣｕ膜を形成する場合は、１７０～１９０℃であることが好ましい。１７０℃未満では、原料の分解が不十分となって金属配線膜中に不純物Ｆ、Ｃが多く含まれるので、実用に適さないためであり、また、１９０℃を超えるとＣｕ膜が凝集してしまう傾向があるためである。 Further, the temperature of the substrate is preferably 170 to 190 ° C. when a Cu film is formed as a metal wiring film. If the temperature is lower than 170 ° C., the raw material is not sufficiently decomposed and the metal wiring film contains a large amount of impurities F and C, which is not suitable for practical use. This is because there is a tendency to end up.
　上記した方法を実施することにより、図４に示すように、ホールを有する基板Ｓ上に金属窒化物膜からなるバリア膜２と金属配線膜３とを形成すれば、バリア膜２と金属配線膜３との密着性が優れたものになる。 By performing the above-described method, as shown in FIG. 4, when the barrier film 2 and the metal wiring film 3 made of a metal nitride film are formed on the substrate S having holes, the barrier film 2 and the metal wiring film are formed. 3 is excellent in adhesion.
　なお、本発明の形成方法においては、不純物の混入や、真空排気または大気開放の操作を考慮すると、バリア膜の形成及び金属配線膜の形成を、同一の装置で各工程を行ったり、大気に触れない状態で基板を搬送するなどして、真空一貫で行うことが好ましい。 In the formation method of the present invention, in consideration of impurity mixing, vacuum evacuation, or opening to the atmosphere, the barrier film formation and the metal wiring film formation are performed in the same apparatus or in the atmosphere. It is preferable to carry out in a consistent vacuum, for example, by transporting the substrate without touching it.
　上述した例では、ホールを有する基板を用い、このホールに金属配線膜を形成する例について示したが、トレンチを有する基板を用いても同様である。また、シリコンウェハー等上にＳｉＯ２等の絶縁体膜が設けられこの絶縁体膜にトレンチやホール等を設けた基板を用いてもよい。さらに、トレンチやホール等を有さず平面的な基板を用いてもよい。 In the above-described example, a substrate having a hole is used and a metal wiring film is formed in the hole. However, the same applies to a substrate having a trench. A substrate in which an insulator film such as SiO 2 is provided on a silicon wafer or the like and a trench or a hole is provided in the insulator film may be used. Furthermore, a planar substrate without a trench or a hole may be used.
　以下、実施例、比較例及び試験例に基づいてさらに詳述するが、本発明はこの実施例により何ら限定されるものではない。
　（実施例１）
　まず、φ３００ｍｍのシリコンウェハー上にＣａｔ－ＡＬＤ法により、厚さ１０ｎｍのＴｉＮからなるバリア膜を形成した。なお、Ｃａｔ－ＡＬＤ法は、Ｃａｔ－ＡＬＤ装置を用い、ＴｉＣｌ４流量０．２ｇ／ｍｉｎ、キャリア（窒素）流量２００ｓｃｃｍ、Ｈ２流量４００ｓｃｃｍ、ＮＨ３流量６００ｓｃｃｍ、基板温度３５０℃、Ｃａｔ（タングステン）温度１７５０℃の条件で行った。 Hereinafter, although it further explains in full detail based on an example, a comparative example, and a test example, the present invention is not limited at all by this example.
Example 1
First, a barrier film made of TiN having a thickness of 10 nm was formed on a silicon wafer having a diameter of 300 mm by the Cat-ALD method. The Cat-ALD method uses a Cat-ALD apparatus, TiCl 4 flow rate 0.2 g / min, carrier (nitrogen) flow rate 200 sccm, H 2 flow rate 400 sccm, NH 3 flow rate 600 sccm, substrate temperature 350 ° C., Cat (tungsten). The measurement was performed at a temperature of 1750 ° C.
　次に、図２（ｂ）に示すような水素プラズマ処理装置を用いて、ＴｉＮからなるバリア膜の表面に、基板にバイアス電圧を印加しながら、水素プラズマを照射した。水素プラズマの照射は、Ｈ２流量２３０ｓｃｃｍ、圧力１．０Ｐａとし、アンテナコイル電圧１９００Ｗ、基板にバイアス電圧を印加するために基板に供給する電力（以下、「基板バイアス値」とも記載する）２００Ｗ、基板温度３５０℃の条件で、プラズマを６０秒放電させることにより行った。なお、基板に２００Ｗの電力を供給しているため、電力密度は０．２８Ｗ／ｃｍ２である。 Next, using a hydrogen plasma processing apparatus as shown in FIG. 2B, the surface of the barrier film made of TiN was irradiated with hydrogen plasma while applying a bias voltage to the substrate. Irradiation with hydrogen plasma is performed at an H 2 flow rate of 230 sccm, a pressure of 1.0 Pa, an antenna coil voltage of 1900 W, power supplied to the substrate to apply a bias voltage to the substrate (hereinafter also referred to as “substrate bias value”) 200 W, Plasma was discharged for 60 seconds under the condition of a substrate temperature of 350 ° C. Note that since 200 W of power is supplied to the substrate, the power density is 0.28 W / cm 2 .
　次に、大気に触れさせることなく金属配線膜を形成する装置に搬送（真空連続搬送）し、ＴｉＮからなるバリア膜上に、ＰＶＤ法により厚さ１０ｎｍのＣｕからなる金属配線膜を形成した。ＰＶＤ法は、圧力０．１Ｐａ、基板温度２０℃の条件で行った。 Next, the film was transported to a device for forming a metal wiring film without being exposed to the atmosphere (vacuum continuous transport), and a metal wiring film made of Cu having a thickness of 10 nm was formed on the barrier film made of TiN by the PVD method. The PVD method was performed under conditions of a pressure of 0.1 Pa and a substrate temperature of 20 ° C.
　（比較例１）
　Ｃａｔ－ＡＬＤ法により厚さ１０ｎｍのＴｉＮからなるバリア膜を形成する代わりに、ＰＶＤ法により厚さ１０ｎｍのＴｉＮからなるバリア膜を形成し、また、ＴｉＮからなるバリア膜の表面に基板にバイアス電圧を印加しながら水素プラズマを照射する操作を行わなかった以外は、実施例１と同様の操作を行った。 (Comparative Example 1)
Instead of forming a barrier film made of TiN having a thickness of 10 nm by the Cat-ALD method, a barrier film made of TiN having a thickness of 10 nm is formed by the PVD method, and a bias voltage is applied to the substrate on the surface of the barrier film made of TiN. The same operation as in Example 1 was performed except that the operation of irradiating hydrogen plasma was not performed while applying.
　（比較例２）
　ＴｉＮからなるバリア膜の表面に基板にバイアス電圧を印加しながら水素プラズマを照射する操作を行わなかった以外は、実施例１と同様の操作を行った。 (Comparative Example 2)
The same operation as in Example 1 was performed except that the operation of irradiating hydrogen plasma while applying a bias voltage to the surface of the barrier film made of TiN was not performed.
　（試験例１）
　実施例１及び比較例１～２のバリア膜及び金属配線膜が形成された基板を、それぞれ３００℃で１時間加熱することにより、バリア膜と金属配線膜との密着性を評価した。３００℃で１時間の加熱前及び加熱後の金属配線膜の表面をＳＥＭ観察した写真を図５に示す。なお、バリア膜と金属配線膜との密着性が悪いと、加熱により金属配線膜が表面張力で凝集して丸まる。 (Test Example 1)
The substrates on which the barrier film and the metal wiring film of Example 1 and Comparative Examples 1 and 2 were formed were each heated at 300 ° C. for 1 hour to evaluate the adhesion between the barrier film and the metal wiring film. FIG. 5 shows photographs obtained by SEM observation of the surface of the metal wiring film before and after heating at 300 ° C. for 1 hour. If the adhesion between the barrier film and the metal wiring film is poor, the metal wiring film is agglomerated and rounded by surface tension due to heating.
　図５に示すように、ＡＬＤ法によりバリア膜を形成し水素プラズマ照射を行った実施例１では、バリア膜表面に残存していたＡＬＤ法の原料ガスＴｉＣｌ４由来のＣｌが、水素イオンや水素ラジカルにより除去されたためか、金属配線膜に凝集がみられず、バリア膜と金属配線膜との密着性が良好であった。一方、水素プラズマ照射を行わなかった比較例２では、金属配線膜が凝集しており、バリア膜と金属配線膜との密着性が悪いことが分かった。これは、Ｃｌがバリア膜表面に残存しているため密着性が悪かったと考えられる。なお、ＰＶＤ法によりバリア膜を形成した比較例１は、原料に純金属を用い、上記ＴｉＣｌ４のような不純物が存在しないためか、実施例１と同様に密着性が良好であった。 As shown in FIG. 5, in Example 1 in which a barrier film was formed by ALD and irradiated with hydrogen plasma, Cl derived from ALD source gas TiCl 4 remaining on the surface of the barrier film was replaced with hydrogen ions or hydrogen. The metal wiring film was not aggregated because it was removed by radicals, and the adhesion between the barrier film and the metal wiring film was good. On the other hand, in Comparative Example 2 in which the hydrogen plasma irradiation was not performed, it was found that the metal wiring film was agglomerated and the adhesion between the barrier film and the metal wiring film was poor. This is probably because Cl remained on the barrier film surface and the adhesion was poor. In Comparative Example 1 in which the barrier film was formed by the PVD method, pure metal was used as a raw material, and the adhesiveness was good as in Example 1, probably because there was no impurity such as TiCl 4 .
　（実施例２）
　実施例１と同様の条件で、Ｃａｔ－ＡＬＤ法により、厚さ１０ｎｍのＴｉＮからなるバリア膜を形成し、ＴｉＮからなるバリア膜の表面に基板にバイアス電圧を印加しながら水素プラズマを照射した後、大気に触れさせることなく金属配線膜を形成する装置に搬送（真空連続搬送）しＴｉＮからなるバリア膜上にＣＶＤ法により厚さ１００ｎｍのＣｕからなる金属配線膜を形成した。なお、ＣＶＤ法は、シュマッカー社製のキュプラセレクト（Ｃｕ＋１（ｈｆａｃ）（ｔｍｖｓ））を原料ガスとして用い、原料流量０．２ｇ／ｍｉｎ、キャリア（アルゴン）流量１０００ｓｃｃｍ、圧力２００Ｐａ、基板温度１８０℃の条件で行った。 (Example 2)
After forming a barrier film made of TiN having a thickness of 10 nm by Cat-ALD method under the same conditions as in Example 1, and irradiating the surface of the barrier film made of TiN with hydrogen plasma while applying a bias voltage to the substrate Then, the film was transported (vacuum continuous transport) to a device for forming a metal wiring film without being exposed to the atmosphere, and a metal wiring film made of Cu having a thickness of 100 nm was formed on the barrier film made of TiN by the CVD method. The CVD method uses a cupra select (Cu + 1 (hfac) (tmvs)) manufactured by Schmucker as a raw material gas, a raw material flow rate of 0.2 g / min, a carrier (argon) flow rate of 1000 sccm, a pressure of 200 Pa, and a substrate temperature of 180 ° C. It went on condition of.
　（実施例３）
　バリア膜に水素プラズマを照射するときの基板バイアス値を、２００Ｗとするかわりに５００Ｗ（電力密度０．７１Ｗ／ｃｍ２）とした以外は、実施例２と同様の操作を行った。 (Example 3)
The same operation as in Example 2 was performed, except that the substrate bias value when the barrier film was irradiated with hydrogen plasma was changed to 500 W (power density 0.71 W / cm 2 ) instead of 200 W.
　（比較例３）
　比較例２と同様の条件で、Ｃａｔ－ＡＬＤ法により、厚さ１０ｎｍのＴｉＮからなるバリア膜を形成した後、ＴｉＮからなるバリア膜上に、実施例２と同様の条件でＣＶＤ法により厚さ１００ｎｍのＣｕからなる金属配線膜を形成した。 (Comparative Example 3)
A barrier film made of TiN having a thickness of 10 nm was formed by the Cat-ALD method under the same conditions as in Comparative Example 2, and then formed on the barrier film made of TiN by the CVD method under the same conditions as in Example 2. A metal wiring film made of 100 nm Cu was formed.
　（試験例２）
　実施例２～３及び比較例３のバリア膜及び金属配線膜が形成された基板について、ＪＩＳ　Ｈ８５０４に規定されているメッキの密着性試験（テープ試験）に準じて、バリア膜と金属配線膜との密着性を評価した。テープを剥がした後の金属配線膜の表面を観察した写真を図６に示す。 (Test Example 2)
For the substrates on which the barrier film and the metal wiring film of Examples 2 to 3 and Comparative Example 3 were formed, the barrier film and the metal wiring film were formed according to the plating adhesion test (tape test) defined in JIS H8504. The adhesion was evaluated. The photograph which observed the surface of the metal wiring film after peeling off a tape is shown in FIG.
　図６に示すように、実施例２は金属配線膜の剥がれがほとんどみられず、バリア膜と金属配線膜との密着性が良好であった。また、実施例３は金属配線膜の剥がれが全くみられず、実施例２よりも密着性が良好であった。このことから、基板バイアスが高いほうが、密着性が良好であることが分かった。これは、水素イオンや水素ラジカルが、基板に印加されたバイアス電圧によって運動エネルギーを得て、バリア膜に衝突したほうが、効率よくバリア膜表面の塩素と反応し、ＨＣｌとなって脱離するためと考えられる。一方、バリア膜に水素プラズマを照射しなかった比較例３では、金属配線膜が剥がれ、バリア膜と金属配線膜には全く密着性がなかった。 As shown in FIG. 6, in Example 2, the metal wiring film was hardly peeled off, and the adhesion between the barrier film and the metal wiring film was good. Further, in Example 3, no peeling of the metal wiring film was observed, and the adhesion was better than that in Example 2. From this, it was found that the higher the substrate bias, the better the adhesion. This is because when hydrogen ions and hydrogen radicals gain kinetic energy from the bias voltage applied to the substrate and collide with the barrier film, they react with chlorine on the surface of the barrier film more efficiently, and are eliminated as HCl. it is conceivable that. On the other hand, in Comparative Example 3 in which the barrier film was not irradiated with hydrogen plasma, the metal wiring film was peeled off, and there was no adhesion between the barrier film and the metal wiring film.
　なお、水素プラズマの照射のときの基板温度を３５０℃とするかわりに、それぞれ１５０℃、１８０℃、２５０℃、３８０℃とした以外は実施例３と同様の操作を行ったところ、１８０℃、２５０℃では実施例３と同様に金属配線膜の剥がれが全くみられなかったが、１５０℃とした場合や３８０℃とした場合は、１８０～３５０℃の範囲内とした場合と比較して、密着性が若干低下した。 The same operation as in Example 3 was performed except that the substrate temperature at the time of irradiation with hydrogen plasma was set to 150 ° C., 180 ° C., 250 ° C., and 380 ° C., respectively. At 250 ° C., no peeling of the metal wiring film was observed as in Example 3. However, when the temperature was set to 150 ° C. or 380 ° C., compared with the case where the temperature was within the range of 180 to 350 ° C. Adhesion was slightly reduced.
　また、基板バイアス値を、それぞれ０Ｗ（電力密度０Ｗ／ｃｍ２）、１５０Ｗ（電力密度０．２１Ｗ／ｃｍ２）、８００Ｗ（電力密度１．１３Ｗ／ｃｍ２）、１０００Ｗ（電力密度１．４２Ｗ／ｃｍ２）とした以外は実施例２と同様の操作を行ったところ、基板バイアス値を８００Ｗとした場合や、１０００Ｗとした場合では、実施例３と同様に金属配線膜の剥がれが全くみられなかったが、０Ｗとした場合や１５０Ｗとした場合は、金属配線膜が剥がれた。また、水素プラズマを照射するときに、基板にバイアス電圧を印加する代わりに真空チャンバの天井部側にバイアス電圧を印加した以外は実施例２と同様の操作を行ったところ、比較例３と同様に、金属配線膜が剥がれた。また、φ３００ｍｍのシリコンウェハーのかわりにφ２００ｍｍのシリコンウェハーを用い基板バイアス値を変化させた以外は実施例２と同様の操作を行ったところ、φ３００ｍｍの場合と同様に、電力密度が０．２５～１．５Ｗ／ｃｍ２の範囲内の場合に、バリア膜と金属配線膜との密着性が特に良好であった。 Further, the substrate bias values are 0 W (power density 0 W / cm 2 ), 150 W (power density 0.21 W / cm 2 ), 800 W (power density 1.13 W / cm 2 ), 1000 W (power density 1.42 W / cm), respectively. when except that the cm 2) was performed in the same manner as in example 2, and when the substrate bias value and 800 W, in the case of the 1000W, in example 3 in the same manner as in the metal wiring film peeling at all Mirare However, when the power was set to 0 W or 150 W, the metal wiring film was peeled off. Further, when the hydrogen plasma was irradiated, the same operation as in Example 2 was performed except that the bias voltage was applied to the ceiling side of the vacuum chamber instead of applying the bias voltage to the substrate. In addition, the metal wiring film was peeled off. Further, the same operation as in Example 2 was performed except that the substrate bias value was changed using a φ200 mm silicon wafer instead of the φ300 mm silicon wafer. As in the case of φ300 mm, the power density was 0.25 to In the range of 1.5 W / cm 2 , the adhesion between the barrier film and the metal wiring film was particularly good.
　（実施例４）
　φ１００ｎｍ、ＡＲ（アスペクト比）＝４．５のホールを有するφ３００ｍｍのウエハーを用いて、図４に示すようなバリア膜及び金属配線膜を形成した。具体的には、まず、Ｃａｔ－ＡＬＤ法により、ＴｉＮからなり厚さ１０ｎｍのバリア膜を形成した。なお、Ｃａｔ－ＡＬＤ法は、実施例１と同様の条件で行った。 Example 4
A barrier film and a metal wiring film as shown in FIG. 4 were formed using a wafer of φ300 mm having holes of φ100 nm and AR (aspect ratio) = 4.5. Specifically, first, a barrier film made of TiN and having a thickness of 10 nm was formed by the Cat-ALD method. The Cat-ALD method was performed under the same conditions as in Example 1.
　次に、ＴｉＮからなるバリア膜の表面に、基板にバイアス電圧を印加しながら、水素プラズマを照射した。水素プラズマの照射は、実施例１と同様の条件で行った。 Next, the surface of the barrier film made of TiN was irradiated with hydrogen plasma while applying a bias voltage to the substrate. The hydrogen plasma irradiation was performed under the same conditions as in Example 1.
　次に、大気に触れさせることなく金属配線膜を形成する装置に搬送（真空連続搬送）し、ＴｉＮからなるバリア膜上に、ＣＶＤ法によりＣｕからなり厚さ２００ｎｍの金属配線膜を形成した。ＣＶＤ法は、実施例２と同様の条件で行った。断面をＳＥＭ観察した写真を図７及び図８に示す。 Next, it was transferred to a device for forming a metal wiring film without being exposed to the atmosphere (vacuum continuous transfer), and a 200 nm thick metal wiring film made of Cu was formed by CVD on the barrier film made of TiN. The CVD method was performed under the same conditions as in Example 2. The photograph which observed the cross section by SEM is shown in FIG.7 and FIG.8.
　（比較例４）
　ＴｉＮからなるバリア膜の表面に基板にバイアス電圧を印加しながら水素プラズマを照射する操作を行わなかった以外は、実施例４と同様の操作を行った。断面をＳＥＭ観察した写真を図７に示す。 (Comparative Example 4)
The same operation as in Example 4 was performed except that the operation of irradiating hydrogen plasma while applying a bias voltage to the surface of the barrier film made of TiN was not performed. The photograph which observed the cross section by SEM is shown in FIG.
　図７に示すように、基板にバイアス電圧を印加しながら水素プラズマをバリア膜に照射した実施例４では、バリア膜と金属配線膜との密着性が良好なため、ボイドを形成せずにＣｕが埋め込まれていた。一方、基板にバイアス電圧を印加しながら水素プラズマをバリア膜に照射する操作を行わなかった比較例４では、バリア膜と金属配線膜との密着性が悪いため、ホール内でＣｕ膜が凝集してボイドが発生していた。 As shown in FIG. 7, in Example 4 in which the barrier film was irradiated with hydrogen plasma while applying a bias voltage to the substrate, the adhesion between the barrier film and the metal wiring film was good, so that Cu was formed without forming voids. Was embedded. On the other hand, in Comparative Example 4 in which the operation of irradiating the barrier film with hydrogen plasma while applying a bias voltage to the substrate was not performed, the adhesion between the barrier film and the metal wiring film was poor, so the Cu film aggregated in the hole. There was a void.
　また、ＴｉＮからなるバリア膜上にＣＶＤ法により厚さ２００ｎｍのＣｕからなる金属配線膜を形成するときの基板温度を１８０℃（図８（ａ））とするかわりに、それぞれ１６０℃、１７０℃、１９０℃、２００℃とした以外は、実施例４と同様の操作を行ったところ、基板温度を１７０℃とした場合や、１９０℃とした場合では、１８０℃とした実施例４と同様にバリア膜と金属配線膜との密着性が良好なためボイドを形成せずにＣｕが埋め込まれていたが、２００℃とした場合は、断面をＳＥＭ観察した写真である図８（ｂ）に示すようにＣｕの埋め込みが不十分であり、また、１６０℃とした場合は、Ｃｕ膜中に不純物ＦやＣが含まれ配線として実用に適さないものであった。 Moreover, instead of setting the substrate temperature to 180 ° C. (FIG. 8A) when forming a metal wiring film made of Cu having a thickness of 200 nm on the barrier film made of TiN by the CVD method, 160 ° C. and 170 ° C., respectively. When the substrate temperature was set to 170 ° C. or 190 ° C. except that the temperature was set to 190 ° C. and 200 ° C. Since the adhesion between the barrier film and the metal wiring film was good, Cu was embedded without forming a void. However, when the temperature is 200 ° C., a cross-sectional SEM observation is shown in FIG. 8B. As described above, Cu was not sufficiently embedded, and when the temperature was set to 160 ° C., impurities F and C were contained in the Cu film, which was not suitable for practical use as a wiring.
　Ｓ、１０１　基板、　　　　　　　　２、１０２　バリア膜
　３　金属配線膜、　　　　　　　　　２０、４０　水素プラズマ処理装置
　２１、４１、６１　真空排気手段、　２２、４２、６２　真空チャンバ
　２３　４３　石英板、　　　　　　　２４、４４、６４　基板支持台
　２５、４５、６５　加熱手段　　　　６６　水素ガス導入手段
　２７、４７、４８、６７　高周波電源
　４９　アンテナコイル　　　　　　　５０　防着板
　６０　水素ラジカル処理装置　　　　７０　触媒線 S, 101 Substrate, 2, 102 Barrier film 3 Metal wiring film, 20, 40 Hydrogen plasma processing apparatus 21, 41, 61 Vacuum exhaust means, 22, 42, 62 Vacuum chamber 23 43 Quartz plate, 24, 44, 64 Substrate support Table 25, 45, 65 Heating means 66 Hydrogen gas introducing means 27, 47, 48, 67 High frequency power supply 49 Antenna coil 50 Deposition plate 60 Hydrogen radical treatment device 70 Catalyst wire

Claims (8)

  1. 　ホールまたはトレンチが形成されている基板上にバリア膜となる金属窒化物膜をＣＶＤ法またはＡＬＤ法により形成し、前記基板側にバイアス電圧を印加しながら前記金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射することを特徴とするバリア膜の形成方法。 A metal nitride film serving as a barrier film is formed on a substrate in which holes or trenches are formed by a CVD method or an ALD method, and a hydrogen plasma or a surface is formed on the surface of the metal nitride film while applying a bias voltage to the substrate side. A method of forming a barrier film, characterized by irradiating with hydrogen radicals.
  2. 　前記基板側に印加するバイアス電圧は、電力密度が０．２５～１．５Ｗ／ｃｍ２となるように電力を供給することにより前記基板側に印加されるものであることを特徴とする請求項１に記載するバリア膜の形成方法。 The bias voltage applied to the substrate side is applied to the substrate side by supplying power so that a power density is 0.25 to 1.5 W / cm 2. 1. A method for forming a barrier film according to 1.
  3. 　前記金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射するときの前記基板の温度は、１８０℃～３５０℃であることを特徴とする請求項１または２に記載するバリア膜の形成方法。 3. The method of forming a barrier film according to claim 1, wherein the temperature of the substrate when the surface of the metal nitride film is irradiated with hydrogen plasma or hydrogen radicals is 180 ° C. to 350 ° C.
  4. 　前記金属窒化物膜は、窒化チタン、窒化タングステン、窒化タンタル、窒化ジルコニウムまたは窒化バナジウムからなる膜であることを特徴とする請求項１～３のいずれか一項に記載するバリア膜の形成方法。 The method for forming a barrier film according to any one of claims 1 to 3, wherein the metal nitride film is a film made of titanium nitride, tungsten nitride, tantalum nitride, zirconium nitride, or vanadium nitride.
  5. 　請求項１～４のいずれか一項に記載するバリア膜の形成方法により形成されたホールまたはトレンチ内のバリア膜上に、ＣＶＤ法またはＰＶＤ法により金属配線膜を形成することを特徴とする金属配線膜の形成方法。 A metal wiring film is formed by a CVD method or a PVD method on a barrier film in a hole or trench formed by the method for forming a barrier film according to any one of claims 1 to 4. A method of forming a wiring film.
  6. 　前記金属配線膜は、銅、アルミニウムまたはタングステンからなる膜であることを特徴とする請求項５に記載する金属配線膜の形成方法。 6. The method of forming a metal wiring film according to claim 5, wherein the metal wiring film is a film made of copper, aluminum or tungsten.
  7. 　前記バリア膜上に前記金属配線膜を形成するときの基板の温度は、１７０℃～１９０℃であることを特徴とする請求項５または６に記載する金属配線膜の形成方法。 The method of forming a metal wiring film according to claim 5 or 6, wherein the temperature of the substrate when forming the metal wiring film on the barrier film is 170 ° C to 190 ° C.
  8. 　ホールまたはトレンチが形成されている基板上にバリア膜となる金属窒化物膜をＣＶＤ法またはＡＬＤ法により形成した後、前記基板側に電力密度が０．２５～１．５Ｗ／ｃｍ２となるように電力を供給することにより基板側にバイアス電圧を印加しながら前記金属窒化物膜の表面に水素プラズマまたは水素ラジカルを照射することによりバリア膜を形成し、その後ホールまたはトレンチ内に形成されたバリア膜上に、ＣＶＤ法またはＰＶＤ法により金属配線膜を形成することを特徴とする金属配線膜の形成方法。 After a metal nitride film serving as a barrier film is formed by CVD or ALD on a substrate in which holes or trenches are formed, the power density is 0.25 to 1.5 W / cm 2 on the substrate side. A barrier film is formed by irradiating the surface of the metal nitride film with hydrogen plasma or hydrogen radical while applying a bias voltage to the substrate side by supplying power to the substrate, and then forming a barrier film in the hole or trench. A method of forming a metal wiring film, comprising forming a metal wiring film on the film by a CVD method or a PVD method.
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