US20020123215A1 - Process for producing barrier film and barrier film thus produced - Google Patents

Process for producing barrier film and barrier film thus produced Download PDF

Info

Publication number
US20020123215A1
US20020123215A1 US10/133,432 US13343202A US2002123215A1 US 20020123215 A1 US20020123215 A1 US 20020123215A1 US 13343202 A US13343202 A US 13343202A US 2002123215 A1 US2002123215 A1 US 2002123215A1
Authority
US
United States
Prior art keywords
gas
reductive
film
melting point
high temperature
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/133,432
Inventor
Masamichi Harada
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ulvac Inc
Original Assignee
Ulvac Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP03804199A external-priority patent/JP4009034B2/en
Priority claimed from JP19202699A external-priority patent/JP3938450B2/en
Application filed by Ulvac Inc filed Critical Ulvac Inc
Priority to US10/133,432 priority Critical patent/US20020123215A1/en
Publication of US20020123215A1 publication Critical patent/US20020123215A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • 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
    • 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
    • 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
    • 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
    • H01L21/76801—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 dielectrics, e.g. smoothing
    • H01L21/76802—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 dielectrics, e.g. smoothing by forming openings in dielectrics
    • H01L21/76807—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 dielectrics, e.g. smoothing by forming openings in dielectrics for dual damascene structures
    • 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
    • H01L21/76801—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 dielectrics, e.g. smoothing
    • H01L21/76802—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 dielectrics, e.g. smoothing by forming openings in dielectrics
    • H01L21/76814—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 dielectrics, e.g. smoothing by forming openings in dielectrics post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
    • 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

  • This invention relates to the technical field of metal interconnecting for semiconductor devices. More particularly, it relates to a process for producing a barrier film which is to be located between a copper interconnecting film and an insulation film, a barrier film which is to be located between a film containing Si, GaAs, etc. and a metal interconnecting for preventing silicidation, and a barrier film which is to be located between a highly dielectric film or a ferroelectric film and an electrode.
  • the sputtering method the heat CVD method or the PE-CVD method is used.
  • a high temperature-melting point metal is employed as a target.
  • a thin nitride film is formed by the following reduction reactions.
  • Formula (1) shows a case wherein tungsten is used, while formula (2) shows another case wherein titanium is used.
  • a barrier film should have a resistance as low as 200 to 300 ⁇ cm.
  • the heat CVD method By the heat CVD method, on the other hand, a uniform barrier thin film can be formed in a viahole.
  • the upper limit of the film-forming temperature in the heat CVD method resides in 400 to 500° C., since the dielectric constants of interlayer insulation films with low dielectric constants would be increased when exposed to a high temperature exceeding 500° C.
  • the resistivity of, for example, a thin tungsten nitride film attains several thousand ⁇ cm, which makes it impossible to give barrier films with low resistance.
  • barrier films with low resistance can be formed at a low temperature by the MOCVD method with the use of organometallic compounds or the plasma CVD method.
  • the organometallic compounds are expensive, while the plasma CVD method has a problem of achieving only poor step coverage. Thus, these methods are not usable in practice.
  • the present invention which has been made to overcome the above-described troubles encountering in the conventional art, aims at providing a barrier film having a value of low resistivity and good step coverage.
  • the present inventors analyzed thin films of high temperature-melting point metal nitrides formed by the conventional heat CVD method and, as a result, found that the high temperature-melting point metal atoms were provided only in an insufficient amount.
  • a tungsten nitride in the conventional art fails to establish the stoichiometric composition (W 2 N) but shows a composition W x N wherein x ranges from about 1.5 to 1.6. It is assumed that such insufficient supply of metal atoms in a nitride might worsen the crystallinity of the thin nitride film, thereby elevating the value of the resistance.
  • the present invention relates to a process for producing a barrier film which comprises the steps of providing a substrate in a vacuum atmosphere, introducing a feedstock gas having a high temperature-melting point metal in its structure and a reductive nitrogen-containing gas having a nitrogen atom into said vacuum atmosphere, and forming a thin film of the nitride of said high temperature-melting point metal on said substrate, wherein a nitrogen-free auxiliary reductive gas is introduced into said vacuum atmosphere.
  • the present invention relates to the process for producing a barrier film, which involves the step of introducing said auxiliary reductive gas together with said feedstock gas and said nitrogen-containing gas into said vacuum atmosphere.
  • the present invention relates to the process for producing a barrier film, which involves the step of introducing said feedstock gas and said nitrogen-containing gas into said vacuum atmosphere without introducing said auxiliary reductive gas.
  • the present invention relates to the process for producing a barrier film, wherein, in the step of introducing said auxiliary reductive gas together with said reductive nitrogen-containing gas and said feedstock gas, said reductive nitrogen-containing gas is introduced at a flow rate once or more higher than the flow rate of said feedstock gas, and said auxiliary reductive gas is introduced at a flow rate once or more but not more than 10 times higher than the flow rate of said reductive nitrogen-containing gas.
  • the present invention relates to the process for producing a barrier film, wherein, in the step of introducing said auxiliary reductive gas together with said reductive nitrogen-containing gas and said feedstock gas, said reductive nitrogen-containing gas is introduced at a flow rate once or more but not more than 5 times higher than the flow rate of said feedstock gas, and said auxiliary reductive gas is introduced at a flow rate 2 times or more but not more than 10 times higher than the flow rate of said reductive nitrogen-containing gas.
  • the present invention relates to the process for producing a barrier film, wherein, in the step of introducing said auxiliary reductive gas together with said reductive nitrogen-containing gas and said feedstock gas, said auxiliary reductive gas is introduced at a flow rate once or more but not more than 15 times higher than the flow rate of the feedstock gas having said high temperature-melting point metal.
  • the present invention relates to the process for producing a barrier film, wherein, in the step of growing the thin film of the nitride of said high temperature-melting point metal, a diluent gas not reacting with said high temperature-melting point metal and a gas having an oxygen atom in its chemical structure are introduced so that the pressure of said vacuum atmosphere is regulated to 1 Pa or more but not more than 100 Pa.
  • the present invention relates to a process for producing a barrier film which comprising the steps of forming a barrier film made of a thin nitride film of a high temperature-melting point metal on a substrate, wherein the surface of said substrate is exposed to a plasma of hydrogen and a plasma of at least one gas selected from among argon, nitrogen and helium gases and then the thin film of the nitride of said high temperature-melting point metal is formed on the surface of the substrate.
  • the invention relates to a barrier film having a thin film of the nitride of a high temperature-melting point metal, wherein said thin nitride film has a content of said high temperature-melting point metal exceeding the stoichiometric composition ratio thereof.
  • the invention relates to a barrier film having a thin nitride film a high temperature-melting point metal formed on a substrate and aiming at preventing the diffusion of metals in a thin interconnecting film formed on said thin nitride film, wherein said thin nitride film is free from silicon.
  • FIGS. 1 ( a ) to ( e ) show the first half of a flow chart illustrating the process of the present invention.
  • FIGS. 2 ( f ) to ( h ) show the second half of a flow chart illustrating the process of the present invention.
  • FIGS. 3 ( i ) to ( j ) show the latter half of a flow chart illustrating the process of the present invention.
  • FIG. 4 shows an example of a CVD apparatus by which the process of the present invention can be embodied.
  • FIG. 5 is a graph which shows relationships between the resistivity of a thin tungsten nitride film formed by the process of the present invention and the flow rates of the feedstock gas, the reductive nitrogen-containing gas and the auxiliary reductive gas.
  • FIG. 6 is a graph which shows a change in the elemental content of a thin tungsten nitride film formed by the process of the present invention depending on the SiH 4 /WF 6 flow rate.
  • FIG. 7 is a graph which shows the composition of tungsten nitride formed by the process of the present invention in the depth direction.
  • FIG. 8 is a graph which shows the composition of tungsten nitride of the conventional art in the depth direction.
  • a feedstock gas having a high temperature-melting point metal atom and a reductive nitrogen-containing gas are introduced into a vacuum atmosphere and the feedstock gas is thus reduced by the reductive nitrogen-containing gas to deposit the nitride of the high temperature-melting point metal, wherein a nitrogen-free auxiliary reductive gas is also introduced into the vacuum atmosphere so as to allow the deposition of the high temperature-melting point metal too.
  • a diluent gas and a gas having an oxygen atom in its structure are simultaneously introduced.
  • oxygen gas, etc. a gas having an oxygen atom in its structure
  • the obtained thin nitride film has a composition wherein the content of the high temperature-melting point metal exceeds the stoichiometric level thereof.
  • the amount of the deposited metal may be smaller than the amount of the deposited nitride.
  • the auxiliary reductive gas should be introduced in a somewhat larger amount than the deposition level, since the auxiliary reductive gas is inferior in the reactivity to the reductive nitrogen-containing gas.
  • the auxiliary reductive gas When the auxiliary reductive gas is introduced at an excessively high rate, on the other hand, the content of the high temperature-melting point metal becomes unnecessarily large and, as a result, the thin film exhibits properties close to the properties of the high temperature-melting point metal rather than those of the nitride.
  • an auxiliary reductive gas containing Si When an auxiliary reductive gas containing Si is employed, there arises a problem that the content of Si in the thin nitride film is increased. Therefore, the reductive nitrogen-containing gas, the auxiliary reductive gas, the diluent gas and the gas having an oxygen atom in its structure should be introduced each at an adequate rate.
  • ammonia gas i.e., the reductive nitrogen-containing gas
  • tungsten hexafluoride i.e., the feedstock gas
  • silane gas i.e., the auxiliary reductive gas
  • FIG. 5 shows the results wherein the abscissa indicates the introduction rate of the silane gas expressed by referring the introduction rate of the ammonia gas as to 1 while the ordinate indicates the resistivity of the thin tungsten nitride film thus formed.
  • the reductive nitrogen-containing gas is introduced at a rate amount once or more larger than the introduction rate of the feedstock gas, while the auxiliary reductive gas is introduced at a rate 2 times or more but not more than 10 times larger than the introduction rate of the reductive nitrogen-containing gas.
  • the practically available resistivity of a barrier film ranges from about 200 to 300 ⁇ cm.
  • the reductive nitrogen-containing gas is introduced preferably at a flow rate 1 time or more but not more than 5 times higher than the flow rate of the feedstock gas and the auxiliary reductive gas is introduced preferably at a flow rate 2 times or more but not more than 5 times higher than the flow rate of the reductive nitrogen-containing gas.
  • FIG. 6 shows the elemental content of each high temperature-melting point metal nitride at various ratios of the flow rate of the feedstock gas to the flow rate of the auxiliary reductive gas in the step of forming high temperature-melting point metal nitrides.
  • WF 6 is used as the feedstock gas
  • SiH 4 is used as the auxiliary reductive gas.
  • Oxygen gas is introduced at 1.5 sccm.
  • the high temperature-melting point metal nitride contains Si when the ratio SiH 4 /WF 6 attains 15 or more.
  • This graph also shows that W x N thin films are formed within the scope of the ratio SiH 4 /WF 6 of 1 to 15 time.
  • FIG. 7 shows the results of Auger spectrochemical analysis of a thin tungsten nitride film formed at a film forming temperature of 400° C. wherein the sputtering time given in the abscissa indicates the depth from the surface. As this graph shows, much tungsten is contained therein (about 4.0 tungsten atoms per nitrogen atom), thereby indicating the effect of the introduction of the auxiliary reductive gas.
  • the barrier film is oxidized when it is taken out into the atmosphere, oxygen is observed on the film surface. Although silicon is seemingly contained in the film, the content thereof is less than the detection limit, i.e., a measurement error.
  • the resistivity can be lowered by using the high temperature-melting point metal in the thin nitride film at a level exceeding the stoichiometric composition ratio thereof while sustaining the barrier performance.
  • a thin nitride film should be adhered closely to the surface of a substrate.
  • a plasma of at least one gas selected from among argon, nitrogen and helium gases, the plasma and the plasma of hydrogen gas, and a plasma of mixed nitrogen the thin nitride film formed on this surface would not peel off even under a load of 1 kg/cm 2 , thereby achieving an adhesiveness usable in the CMP process.
  • the silicon reacts with the high temperature-melting point metal (tungsten, etc.) at a high temperature to form a silicon compound such as tungsten silicide to thereby increase the resistivity. Since the thin nitride film of the present invention is free form silicon, no silicon compound is formed and thus the resistivity can be stabilized at a low level.
  • the high temperature-melting point metal tungsten, etc.
  • FIG. 8 shows the results of Auger spectrochemical analysis of a thin tungsten nitride film formed by the CVD method of the conventional art at a film forming temperature of 400° C.
  • This thin film contains about 1.7 tungsten atoms per nitrogen atom, i.e., showing a smaller tungsten content. It also shows a high resistivity of 1000 ⁇ cm or more.
  • the pressure In the step of the formation of the thin nitride film of the high temperature-melting point metal, it is preferable to regulate the pressure to 1 Pa or more but not more than 10000 Pa, still preferably 1 Pa or more but not more than 100 Pa.
  • FIGS. 1 ( a ) to ( d ) show a flow chart which shows an example of the embodiment of the present invention.
  • the numerical symbol 20 shows a substrate to be treated.
  • This substrate 20 has a semiconductor substrate 21 made of single silicon crystal on the surface of which a primary coat film 22 and an insulation film 23 made of silicon oxide are formed.
  • the primary film 22 and the insulation film 23 are provided with a hole 31 .
  • the surface of semiconductor substrate 21 is exposed at a bottom 32 of the hole 31 .
  • a barrier film is to be formed on the surface of this substrate 20 .
  • the numerical symbol 50 shows a CVD apparatus whereby the present invention can be embodied.
  • This CVD apparatus 50 has a vacuum chamber 51 which is connected to a transport room (not shown).
  • the vacuum chamber 51 is provided with a substrate holder 53 in the bottom side and an electrode 55 in the top side.
  • the substrate 20 is first brought into the transport room and the transport room and the vacuum chamber 51 are evacuated. Next, a gate valve 52 between the vacuum chamber 51 and the transport room is opened and then the substrate 20 is brought into the CVD apparatus 50 .
  • the substrate holder 53 is provided with a substrate elevator unit 54 with which the substrate brought into the vacuum chamber 51 is placed on the substrate holder 53 .
  • the substrate 20 is thus placed on the substrate holder 53 .
  • the heater in the substrate holder 53 is switched on and thus the substrate 20 is heated to a temperature of not lower than 300° C. but not higher than 400° C.
  • the vacuum chamber 51 is provided with a gas inlet system 57 through which argon gas and ammonia gas are introduced into the vacuum chamber 51 each at a prescribed flow rate.
  • argon gas and ammonia gas are introduced into the vacuum chamber 51 each at a prescribed flow rate.
  • ionized nitrogen and hydrogen are liberated from the ammonia gas.
  • the ionized argon gas serving as a diluent gas is mixed with the ionized nitrogen and hydrogen to give a plasma.
  • the insulation film 23 on the surface of the substrate 20 is faced closely to the electrode 55 . As the plasma is formed, the surface of the insulation film 23 and the surface of the semiconductor substrate 21 at the bottom of the hole 31 are exposed to the plasma and the organic deposits are decomposed (i.e., cleaning).
  • the cleaning is performed at an ammonia gas flow rate of 75 sccm, an argon gas flow rate of 240 sccm, under a pressure of 40 Pa and at a high-frequency electrical power of 100 W. After cleaning for about 50 seconds, the application of the high-frequency voltage is stopped to thereby extinguish the plasma.
  • argon (Ar) gas is used in this case, it can be substituted by nitrogen (N 2 ) gas, helium (He) gas or a mixture thereof.
  • the tungsten hexafluoride serves as the feedstock gas and the ammonia gas serves as the reductive nitrogen-containing gas.
  • the reaction of reducing the feedstock gas proceeds.
  • the ammonia gas contains nitrogen, tungsten nitride is deposited on the surface of the insulation film 23 and on the surface of the semiconductor substrate 21 in the hole 31 due to the reduction reaction represented by the above formula (1).
  • the silane gas introduced into the vacuum chamber 51 also has reductive properties, it is inferior in reactivity to the ammonia gas and, therefore, serves as the auxiliary reductive gas. Since the silane gas has no nitrogen atom, the feedstock gas is reduced thereby in accordance with the following formula (3) and thus metal tungsten is deposited.
  • metal tungsten When metal tungsten is deposited, it is incorporated into the thin tungsten nitride film under growing. That is to say, metal tungsten is supplied during the growth of the thin tungsten nitride film. When the thin tungsten nitride film grows at a low temperature, the deficiency of tungsten is thus compensated for and a barrier film (a thin tungsten nitride film) having a composition close to the stoichiometric composition or one having a high temperature-melting point metal content exceeding the stoichiometric level can be formed.
  • a barrier film a thin tungsten nitride film having a composition close to the stoichiometric composition or one having a high temperature-melting point metal content exceeding the stoichiometric level can be formed.
  • the thin tungsten nitride film may grow under, for example, the following conditions; substrate temperature: 380° C.; feedstock gas flow rate: 5 sccm; reductive nitrogen-containing gas flow rate: 13 sccm; auxiliary reductive gas flow rate: 39 sccm; argon gas flow rate: 240 sccm; oxygen gas introduction rate: 1.5 sccm; pressure: 40 Pa.
  • the supply of the reductive nitrogen-containing gas is ceased and the flow rate of the auxiliary reductive gas is increased.
  • the feedstock gas is reduced by the auxiliary reductive gas and metal tungsten is deposited.
  • the numerical symbol 25 shows a thin metal tungsten film growing on the surface of the thin nitride film 24 .
  • the thin metal tungsten film may be formed under, for example, the following conditions; substrate temperature: 380° C.; feedstock gas flow rate: 20 sccm; auxiliary reductive gas flow rate: 5 sccm; diluent (argon) gas introduction rate: 240 sccm; pressure: 40 Pa.
  • the thin nitride film 24 has a favorable barrier performance against copper, it has a higher resistivity than that of the high temperature-melting point metal.
  • the film of the high temperature-melting point metal for example, thin metal tungsten film, etc.
  • the film of the high temperature-melting point metal has a poor barrier performance against copper but has a much lower resistivity than that of the thin nitride film 24 .
  • a thin nitride film 24 is formed as a barrier film and a thin high temperature-melting point metal film is laminated thereon as in the above-described case, the resistivity can be lowered while sustaining the favorable barrier performance against copper.
  • a thin nitride film may be formed on a high temperature-melting point metal film or the thin nitride film may be formed as a single layer.
  • the substrate 20 is taken out from the CVD apparatus 50 . Then a thin copper film is grown on the surface of the thin high temperature-melting point metal film 25 by the metal plating method, the sputtering method, etc.
  • the numerical symbol 26 shows this thin copper film 26 .
  • the surface is abraded by the CMP method to thereby eliminate the thin copper film 26 , the thin nitride film 24 and the thin metal film 25 on the insulation film 23 .
  • a interconnecting film 27 made of the thin copper film 26 is formed in the hole 31 .
  • the thin nitride film 24 is located between the interconnecting film 27 and the semiconductor substrate 21 and between the interconnecting film 27 and the insulation film 23 so as to prevent copper from diffusion.
  • a thin nitride film (a thin tungsten nitride film) is formed under the same conditions as in forming the thin nitride film shown in FIG. 1( b ).
  • the numerical symbol 33 in FIG. 2( h ) shows the thus formed thin nitride film which covers the inner face of the groove or hole 38 and the surface of the insulation film 44 and the surface of the interconnecting film 27 .
  • the thin copper film 34 is grown by the metal plating method or the sputtering method, as shown in FIG. 3).
  • the groove or hole 38 is filled with the thin copper film 34 .
  • an interconnecting film 35 is formed by the thin copper film 34 filled into the groove or hole 38 , as shown in FIG. 3( j ).
  • the barrier film 33 is located between the interconnecting film 35 and the insulation films 42 and 44 , the diffusion of copper into the insulation films 42 and 44 can be prevented.
  • a thin tungsten nitride film is formed by using tungsten as the high temperature-melting point metal, ammonia gas as the reductive nitrogen-containing gas and silane gas as the auxiliary reductive gas.
  • tungsten hexafluoride is used as the feedstock gas in the above case, it is also possible to use W(CO) 6 gas therefor.
  • the present invention involves in its scope cases where barrier films are produced by using high temperature-melting point metals other than tungsten and forming thin films of the nitrides thereof.
  • titanium (Ti) is used as the high temperature-melting point metal
  • titanium halide gases TiF 4 , TiCl 4 , etc.
  • tantalum (Ta) is used as the high temperature-melting point metal
  • tantalum halide gases (TaCl 5 , etc.) are usable as the feedstock gas. It is also possible to use halides of Mo or Nb as the feedstock gas.
  • reductive nitrogen-containing gas containing a nitrogen atom use can be made of N 2 H 4 gas, NF 3 gas, N 2 0 gas, etc. in addition to NH 3 gas.
  • the nitrogen-free auxiliary reductive gas use can be made of H 2 gas, Si 2 H 6 gas, PH 3 gas, B 2 H 6 gas etc. in addition to SiH 4 gas.
  • diluent gas it is also possible to use argon gas, nitrogen gas, helium gas or a mixture of these gases.
  • the cleaning conditions as described above are given merely by way of example. Therefore, the cleaning may be performed under different conditions. For example, similar effects can be achieved by carrying out the cleaning for 60 seconds at an argon gas flow rate of 100 sccm, under a pressure of 1.0 Pa at a high-frequency electric power of 150W.
  • additional cleaning may be performed by adding ammonia gas to the argon gas.
  • a barrier film (a thin film of the nitride of a high temperature-melting point metal) having a low resistance can be formed by the CVD method at a temperature of 500° C. or lower, in particular, from 350 to 450° C. Therefore, interlayer insulation films are not damaged thereby.
  • the thin nitride film is formed by the heat CVD method, which makes it possible to achieve good step coverage.

Abstract

A thin nitride film having a low resistance is formed at a low film-forming temperature.
In the step of forming a thin nitride film 24 of a high temperature-melting point metal by introducing a feedstock gas having the high temperature-melting point metal and a reductive nitrogen-containing gas having a nitrogen atom into a vacuum atmosphere, an auxiliary reductive gas free from nitrogen is also introduced. The high temperature-melting point metal deposited due to the auxiliary reductive gas compensates for the deficiency of the high temperature-melting point metal of the deposited nitride and thus enable the growth of the thin nitride film 24 having a low resistance.

Description

    FIELD OF THE INVENTION
  • This invention relates to the technical field of metal interconnecting for semiconductor devices. More particularly, it relates to a process for producing a barrier film which is to be located between a copper interconnecting film and an insulation film, a barrier film which is to be located between a film containing Si, GaAs, etc. and a metal interconnecting for preventing silicidation, and a barrier film which is to be located between a highly dielectric film or a ferroelectric film and an electrode. [0001]
    • BACKGROUND OF THE INVENTION
  • In recent years, it has been required to more and more speed up the operations of semiconductor devices. To satisfy this requirement, studies have been undertaken on low-resistant copper interconnectings as a substitute for aluminum interconnectings. [0002]
  • However, copper occurs as an impurity in semiconductor crystals. In addition, it suffers from a problem of having a large diffusion coefficient in silicon crystals or silicon oxide. Therefore, it has been a practice that a thin film comprising the nitride of a high temperature-melting point metal (a thin tungsten nitride film, etc.) is formed as a barrier film on the surface of a silicon substrate or a thin silicon oxide film and then a copper interconnecting film is formed on the surface of the barrier film. [0003]
  • To form such a barrier film, the sputtering method, the heat CVD method or the PE-CVD method is used. In the sputtering method, a high temperature-melting point metal is employed as a target. In the heat CVD method, a thin nitride film is formed by the following reduction reactions. Formula (1) shows a case wherein tungsten is used, while formula (2) shows another case wherein titanium is used. [0004]
  • 4WF6+8NH3→2W2N+24HF+3N2   (1)
  • TiCl4+NH3→TiN+2HCl+½H2   (2)
  • In case of forming a semiconductor device with multi-layered interconnecting, it is needed to laminate copper interconnectings while inserting interlayer insulation films between them. In a semiconductor device to be operated at a high speed, the resistance of the copper interconnectings as well as the capacity of the interlayer insulation films and the resistance of the barrier films should be lowered so as to minimize signal transfer delay. More concretely speaking, a barrier film should have a resistance as low as 200 to 300 μΩcm. [0005]
  • Although a thin nitride film having a low resistance can be formed by the sputtering method, only poor step coverage can be achieved thereby. Thus, no uniform barrier film can be formed in a viahole with a high aspect ratio by this method. [0006]
  • By the heat CVD method, on the other hand, a uniform barrier thin film can be formed in a viahole. However, the upper limit of the film-forming temperature in the heat CVD method resides in 400 to 500° C., since the dielectric constants of interlayer insulation films with low dielectric constants would be increased when exposed to a high temperature exceeding 500° C. At such a low film-forming temperature, the resistivity of, for example, a thin tungsten nitride film attains several thousand μΩcm, which makes it impossible to give barrier films with low resistance. [0007]
  • With respect to the CVD methods, barrier films with low resistance can be formed at a low temperature by the MOCVD method with the use of organometallic compounds or the plasma CVD method. However, the organometallic compounds are expensive, while the plasma CVD method has a problem of achieving only poor step coverage. Thus, these methods are not usable in practice. [0008]
    • SUMMARY OF THE INVENTION
  • The present invention, which has been made to overcome the above-described troubles encountering in the conventional art, aims at providing a barrier film having a value of low resistivity and good step coverage. [0009]
  • The present inventors analyzed thin films of high temperature-melting point metal nitrides formed by the conventional heat CVD method and, as a result, found that the high temperature-melting point metal atoms were provided only in an insufficient amount. In the case of tungsten, for example, a tungsten nitride in the conventional art fails to establish the stoichiometric composition (W[0010] 2N) but shows a composition WxN wherein x ranges from about 1.5 to 1.6. It is assumed that such insufficient supply of metal atoms in a nitride might worsen the crystallinity of the thin nitride film, thereby elevating the value of the resistance.
  • In the present invention which has been completed based on the above-described finding, attempts are made to approximate the composition of the nitride of a high temperature-melting point metal closely to the stoichiometric level. To achieve this object, the present invention relates to a process for producing a barrier film which comprises the steps of providing a substrate in a vacuum atmosphere, introducing a feedstock gas having a high temperature-melting point metal in its structure and a reductive nitrogen-containing gas having a nitrogen atom into said vacuum atmosphere, and forming a thin film of the nitride of said high temperature-melting point metal on said substrate, wherein a nitrogen-free auxiliary reductive gas is introduced into said vacuum atmosphere. [0011]
  • The present invention relates to the process for producing a barrier film, which involves the step of introducing said auxiliary reductive gas together with said feedstock gas and said nitrogen-containing gas into said vacuum atmosphere. [0012]
  • The present invention relates to the process for producing a barrier film, which involves the step of introducing said feedstock gas and said nitrogen-containing gas into said vacuum atmosphere without introducing said auxiliary reductive gas. [0013]
  • The present invention relates to the process for producing a barrier film, wherein, in the step of introducing said auxiliary reductive gas together with said reductive nitrogen-containing gas and said feedstock gas, said reductive nitrogen-containing gas is introduced at a flow rate once or more higher than the flow rate of said feedstock gas, and said auxiliary reductive gas is introduced at a flow rate once or more but not more than 10 times higher than the flow rate of said reductive nitrogen-containing gas. [0014]
  • The present invention relates to the process for producing a barrier film, wherein, in the step of introducing said auxiliary reductive gas together with said reductive nitrogen-containing gas and said feedstock gas, said reductive nitrogen-containing gas is introduced at a flow rate once or more but not more than 5 times higher than the flow rate of said feedstock gas, and said auxiliary reductive gas is introduced at a [0015] flow rate 2 times or more but not more than 10 times higher than the flow rate of said reductive nitrogen-containing gas.
  • The present invention relates to the process for producing a barrier film, wherein, in the step of introducing said auxiliary reductive gas together with said reductive nitrogen-containing gas and said feedstock gas, said auxiliary reductive gas is introduced at a flow rate once or more but not more than 15 times higher than the flow rate of the feedstock gas having said high temperature-melting point metal. [0016]
  • The present invention relates to the process for producing a barrier film, wherein, in the step of growing the thin film of the nitride of said high temperature-melting point metal, a diluent gas not reacting with said high temperature-melting point metal and a gas having an oxygen atom in its chemical structure are introduced so that the pressure of said vacuum atmosphere is regulated to 1 Pa or more but not more than 100 Pa. [0017]
  • The present invention relates to a process for producing a barrier film which comprising the steps of forming a barrier film made of a thin nitride film of a high temperature-melting point metal on a substrate, wherein the surface of said substrate is exposed to a plasma of hydrogen and a plasma of at least one gas selected from among argon, nitrogen and helium gases and then the thin film of the nitride of said high temperature-melting point metal is formed on the surface of the substrate. [0018]
  • The invention relates to a barrier film having a thin film of the nitride of a high temperature-melting point metal, wherein said thin nitride film has a content of said high temperature-melting point metal exceeding the stoichiometric composition ratio thereof. [0019]
  • The invention relates to a barrier film having a thin nitride film a high temperature-melting point metal formed on a substrate and aiming at preventing the diffusion of metals in a thin interconnecting film formed on said thin nitride film, wherein said thin nitride film is free from silicon.[0020]
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIGS. [0021] 1(a) to (e) show the first half of a flow chart illustrating the process of the present invention.
  • FIGS. [0022] 2(f) to (h) show the second half of a flow chart illustrating the process of the present invention.
  • FIGS. [0023] 3(i) to (j) show the latter half of a flow chart illustrating the process of the present invention.
  • FIG. 4 shows an example of a CVD apparatus by which the process of the present invention can be embodied. [0024]
  • FIG. 5 is a graph which shows relationships between the resistivity of a thin tungsten nitride film formed by the process of the present invention and the flow rates of the feedstock gas, the reductive nitrogen-containing gas and the auxiliary reductive gas. [0025]
  • FIG. 6 is a graph which shows a change in the elemental content of a thin tungsten nitride film formed by the process of the present invention depending on the SiH[0026] 4/WF6 flow rate.
  • FIG. 7 is a graph which shows the composition of tungsten nitride formed by the process of the present invention in the depth direction. [0027]
  • FIG. 8 is a graph which shows the composition of tungsten nitride of the conventional art in the depth direction.[0028]
  • In these drawings, each numerical symbol has the following meaning: [0029]
  • [0030] 20: substrate
  • [0031] 24, 33: thin nitride films (barrier films)
  • [0032] 25: thin metal film
  • [0033] 27, 35: interconnecting films.
    • DETAILED DESCRIPTION OF THE INVENTION
  • In the present invention which has the above-described constitution, a feedstock gas having a high temperature-melting point metal atom and a reductive nitrogen-containing gas are introduced into a vacuum atmosphere and the feedstock gas is thus reduced by the reductive nitrogen-containing gas to deposit the nitride of the high temperature-melting point metal, wherein a nitrogen-free auxiliary reductive gas is also introduced into the vacuum atmosphere so as to allow the deposition of the high temperature-melting point metal too. [0034]
  • Further, a diluent gas and a gas having an oxygen atom in its structure (oxygen gas, etc.) are simultaneously introduced. As a result, it becomes possible to form a nitride film having improved barrier performance and further lowered resistivity, compared with a case where no oxygen atom-containing gas is introduced. [0035]
  • When the nitride of the high temperature-melting point metal is deposited at a low temperature, the high temperature-melting point metal in the thin nitride film becomes deficient. However, the high temperature-melting point metal atoms deposited by the auxiliary reductive gas compensate for the deficiency. Thus, the obtained thin nitride film has a composition wherein the content of the high temperature-melting point metal exceeds the stoichiometric level thereof. [0036]
  • The amount of the deposited metal may be smaller than the amount of the deposited nitride. However, the auxiliary reductive gas should be introduced in a somewhat larger amount than the deposition level, since the auxiliary reductive gas is inferior in the reactivity to the reductive nitrogen-containing gas. [0037]
  • When the auxiliary reductive gas is introduced at an excessively high rate, on the other hand, the content of the high temperature-melting point metal becomes unnecessarily large and, as a result, the thin film exhibits properties close to the properties of the high temperature-melting point metal rather than those of the nitride. When an auxiliary reductive gas containing Si is employed, there arises a problem that the content of Si in the thin nitride film is increased. Therefore, the reductive nitrogen-containing gas, the auxiliary reductive gas, the diluent gas and the gas having an oxygen atom in its structure should be introduced each at an adequate rate. [0038]
  • For example, ammonia gas (i.e., the reductive nitrogen-containing gas) is introduced at rates 1.0, 2.6 and 5.0 times higher than that of tungsten hexafluoride (i.e., the feedstock gas) and the ratio of silane gas (i.e., the auxiliary reductive gas) to the ammonia gas is varied. [0039]
  • FIG. 5 shows the results wherein the abscissa indicates the introduction rate of the silane gas expressed by referring the introduction rate of the ammonia gas as to 1 while the ordinate indicates the resistivity of the thin tungsten nitride film thus formed. [0040]
  • As this graph shows, it is preferable that the reductive nitrogen-containing gas is introduced at a rate amount once or more larger than the introduction rate of the feedstock gas, while the auxiliary reductive gas is introduced at a [0041] rate 2 times or more but not more than 10 times larger than the introduction rate of the reductive nitrogen-containing gas.
  • The practically available resistivity of a barrier film ranges from about 200 to 300 μΩcm. Thus, it can be understood from this graph that the reductive nitrogen-containing gas is introduced preferably at a [0042] flow rate 1 time or more but not more than 5 times higher than the flow rate of the feedstock gas and the auxiliary reductive gas is introduced preferably at a flow rate 2 times or more but not more than 5 times higher than the flow rate of the reductive nitrogen-containing gas.
  • FIG. 6 shows the elemental content of each high temperature-melting point metal nitride at various ratios of the flow rate of the feedstock gas to the flow rate of the auxiliary reductive gas in the step of forming high temperature-melting point metal nitrides. In this case, WF[0043] 6 is used as the feedstock gas and SiH4 is used as the auxiliary reductive gas. Oxygen gas is introduced at 1.5 sccm.
  • As this graph shows, the high temperature-melting point metal nitride (WN in this case) contains Si when the ratio SiH[0044] 4/WF6 attains 15 or more. This graph also shows that WxN thin films are formed within the scope of the ratio SiH4/WF6 of 1 to 15 time.
  • FIG. 7 shows the results of Auger spectrochemical analysis of a thin tungsten nitride film formed at a film forming temperature of 400° C. wherein the sputtering time given in the abscissa indicates the depth from the surface. As this graph shows, much tungsten is contained therein (about 4.0 tungsten atoms per nitrogen atom), thereby indicating the effect of the introduction of the auxiliary reductive gas. [0045]
  • Since the barrier film is oxidized when it is taken out into the atmosphere, oxygen is observed on the film surface. Although silicon is seemingly contained in the film, the content thereof is less than the detection limit, i.e., a measurement error. [0046]
  • Thus, the resistivity can be lowered by using the high temperature-melting point metal in the thin nitride film at a level exceeding the stoichiometric composition ratio thereof while sustaining the barrier performance. [0047]
  • In the CMP process, a thin nitride film should be adhered closely to the surface of a substrate. When the surface of the substrate is cleaned with a plasma of at least one gas selected from among argon, nitrogen and helium gases, the plasma and the plasma of hydrogen gas, and a plasma of mixed nitrogen, the thin nitride film formed on this surface would not peel off even under a load of 1 kg/cm[0048] 2, thereby achieving an adhesiveness usable in the CMP process.
  • When the thin nitride film contains silicon, the silicon reacts with the high temperature-melting point metal (tungsten, etc.) at a high temperature to form a silicon compound such as tungsten silicide to thereby increase the resistivity. Since the thin nitride film of the present invention is free form silicon, no silicon compound is formed and thus the resistivity can be stabilized at a low level. [0049]
  • For comparison, FIG. 8 shows the results of Auger spectrochemical analysis of a thin tungsten nitride film formed by the CVD method of the conventional art at a film forming temperature of 400° C. This thin film contains about 1.7 tungsten atoms per nitrogen atom, i.e., showing a smaller tungsten content. It also shows a high resistivity of 1000 μΩcm or more. [0050]
  • In the step of the formation of the thin nitride film of the high temperature-melting point metal, it is preferable to regulate the pressure to 1 Pa or more but not more than 10000 Pa, still preferably 1 Pa or more but not more than 100 Pa. [0051]
    • DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION
  • Now, embodiments of the present invention will be described by reference to the attached drawings. [0052]
  • FIGS. [0053] 1(a) to (d) show a flow chart which shows an example of the embodiment of the present invention. In FIG. 1(a), the numerical symbol 20 shows a substrate to be treated. This substrate 20 has a semiconductor substrate 21 made of single silicon crystal on the surface of which a primary coat film 22 and an insulation film 23 made of silicon oxide are formed. The primary film 22 and the insulation film 23 are provided with a hole 31. The surface of semiconductor substrate 21 is exposed at a bottom 32 of the hole 31.
  • A barrier film is to be formed on the surface of this [0054] substrate 20.
  • In FIG. 4, the [0055] numerical symbol 50 shows a CVD apparatus whereby the present invention can be embodied. This CVD apparatus 50 has a vacuum chamber 51 which is connected to a transport room (not shown). The vacuum chamber 51 is provided with a substrate holder 53 in the bottom side and an electrode 55 in the top side.
  • When a barrier film is to be formed on the [0056] substrate 20 by using this CVD apparatus 50, the substrate 20 is first brought into the transport room and the transport room and the vacuum chamber 51 are evacuated. Next, a gate valve 52 between the vacuum chamber 51 and the transport room is opened and then the substrate 20 is brought into the CVD apparatus 50.
  • The [0057] substrate holder 53 is provided with a substrate elevator unit 54 with which the substrate brought into the vacuum chamber 51 is placed on the substrate holder 53. In FIG. 4, the substrate 20 is thus placed on the substrate holder 53.
  • Subsequently, the heater in the [0058] substrate holder 53 is switched on and thus the substrate 20 is heated to a temperature of not lower than 300° C. but not higher than 400° C.
  • The [0059] vacuum chamber 51 is provided with a gas inlet system 57 through which argon gas and ammonia gas are introduced into the vacuum chamber 51 each at a prescribed flow rate. By applying a high-frequency voltage between the substrate holder 53 and the electrode 55, ionized nitrogen and hydrogen are liberated from the ammonia gas. In this step, the ionized argon gas serving as a diluent gas is mixed with the ionized nitrogen and hydrogen to give a plasma.
  • The [0060] insulation film 23 on the surface of the substrate 20 is faced closely to the electrode 55. As the plasma is formed, the surface of the insulation film 23 and the surface of the semiconductor substrate 21 at the bottom of the hole 31 are exposed to the plasma and the organic deposits are decomposed (i.e., cleaning).
  • The cleaning is performed at an ammonia gas flow rate of 75 sccm, an argon gas flow rate of 240 sccm, under a pressure of 40 Pa and at a high-frequency electrical power of 100 W. After cleaning for about 50 seconds, the application of the high-frequency voltage is stopped to thereby extinguish the plasma. Although argon (Ar) gas is used in this case, it can be substituted by nitrogen (N[0061] 2) gas, helium (He) gas or a mixture thereof.
  • Next, the flow rates of the ammonia gas and the argon gas are changed and, at the same time, tungsten hexafluoride (WF[0062] 6) gas, silane gas and oxygen gas are introduced into the vacuum chamber 51 through the gas inlet system 57 together with the ammonia gas and the argon gas.
  • Since the ammonia gas is superior in the reactivity to the silane gas, the tungsten hexafluoride serves as the feedstock gas and the ammonia gas serves as the reductive nitrogen-containing gas. Thus, the reaction of reducing the feedstock gas proceeds. Since the ammonia gas contains nitrogen, tungsten nitride is deposited on the surface of the [0063] insulation film 23 and on the surface of the semiconductor substrate 21 in the hole 31 due to the reduction reaction represented by the above formula (1).
  • Although the silane gas introduced into the [0064] vacuum chamber 51 also has reductive properties, it is inferior in reactivity to the ammonia gas and, therefore, serves as the auxiliary reductive gas. Since the silane gas has no nitrogen atom, the feedstock gas is reduced thereby in accordance with the following formula (3) and thus metal tungsten is deposited.
  • WF6+({fraction (3/2)})SiH4→W+({fraction (3/2)})SiF4+3H2   (3)
  • When metal tungsten is deposited, it is incorporated into the thin tungsten nitride film under growing. That is to say, metal tungsten is supplied during the growth of the thin tungsten nitride film. When the thin tungsten nitride film grows at a low temperature, the deficiency of tungsten is thus compensated for and a barrier film (a thin tungsten nitride film) having a composition close to the stoichiometric composition or one having a high temperature-melting point metal content exceeding the stoichiometric level can be formed. [0065]
  • The thin tungsten nitride film may grow under, for example, the following conditions; substrate temperature: 380° C.; feedstock gas flow rate: 5 sccm; reductive nitrogen-containing gas flow rate: 13 sccm; auxiliary reductive gas flow rate: 39 sccm; argon gas flow rate: 240 sccm; oxygen gas introduction rate: 1.5 sccm; pressure: 40 Pa. [0066]
  • When the feedstock gas is subjected to the reduction reaction by the reductive nitrogen-containing gas and the auxiliary reductive gas for a prescribed period of time, a thin tungsten nitride film is formed on the surface of [0067] insulation film 23 and on the surface of the semiconductor substrate 21, as shown in FIG. 1(b) 24.
  • Next, the supply of the reductive nitrogen-containing gas is ceased and the flow rate of the auxiliary reductive gas is increased. Thus, the feedstock gas is reduced by the auxiliary reductive gas and metal tungsten is deposited. In FIG. 1([0068] c), the numerical symbol 25 shows a thin metal tungsten film growing on the surface of the thin nitride film 24.
  • The thin metal tungsten film may be formed under, for example, the following conditions; substrate temperature: 380° C.; feedstock gas flow rate: 20 sccm; auxiliary reductive gas flow rate: 5 sccm; diluent (argon) gas introduction rate: 240 sccm; pressure: 40 Pa. [0069]
  • Although the [0070] thin nitride film 24 has a favorable barrier performance against copper, it has a higher resistivity than that of the high temperature-melting point metal. On the other hand, the film of the high temperature-melting point metal (for example, thin metal tungsten film, etc.) has a poor barrier performance against copper but has a much lower resistivity than that of the thin nitride film 24.
  • When a [0071] thin nitride film 24 is formed as a barrier film and a thin high temperature-melting point metal film is laminated thereon as in the above-described case, the resistivity can be lowered while sustaining the favorable barrier performance against copper.
  • On the contrary, a thin nitride film may be formed on a high temperature-melting point metal film or the thin nitride film may be formed as a single layer. [0072]
  • After allowing the [0073] thin tungsten film 25 to grow for 20 to 30 seconds under the above-described conditions, the substrate 20 is taken out from the CVD apparatus 50. Then a thin copper film is grown on the surface of the thin high temperature-melting point metal film 25 by the metal plating method, the sputtering method, etc. In FIG. 1(d), the numerical symbol 26 shows this thin copper film 26.
  • After the formation of the [0074] thin copper film 26, the surface is abraded by the CMP method to thereby eliminate the thin copper film 26, the thin nitride film 24 and the thin metal film 25 on the insulation film 23. Thus, a interconnecting film 27 made of the thin copper film 26 is formed in the hole 31. The thin nitride film 24 is located between the interconnecting film 27 and the semiconductor substrate 21 and between the interconnecting film 27 and the insulation film 23 so as to prevent copper from diffusion.
  • Next, [0075] primary films 41 and 43 and insulation films 42 and 44 are laminated alternately and the surface of the interconnecting film 27 is windowed to form a hole or a groove, as shown in FIG. 2(g). In FIG. 2(g), the numerical symbol 38 shows the groove or hole. The interconnecting film 27 is exposed on the bottom of this groove or hole 38.
  • Then the [0076] substrate 20 is brought into the CVD apparatus 50 and a thin nitride film (a thin tungsten nitride film) is formed under the same conditions as in forming the thin nitride film shown in FIG. 1(b).
  • The [0077] numerical symbol 33 in FIG. 2(h) shows the thus formed thin nitride film which covers the inner face of the groove or hole 38 and the surface of the insulation film 44 and the surface of the interconnecting film 27.
  • Subsequently, the [0078] thin copper film 34 is grown by the metal plating method or the sputtering method, as shown in FIG. 3). Thus, the groove or hole 38 is filled with the thin copper film 34.
  • Finally, the surface is abraded by the CMP method. Thus, an interconnecting [0079] film 35 is formed by the thin copper film 34 filled into the groove or hole 38, as shown in FIG. 3(j).
  • Since the [0080] barrier film 33 is located between the interconnecting film 35 and the insulation films 42 and 44, the diffusion of copper into the insulation films 42 and 44 can be prevented.
  • In the above-described case, a thin tungsten nitride film is formed by using tungsten as the high temperature-melting point metal, ammonia gas as the reductive nitrogen-containing gas and silane gas as the auxiliary reductive gas. Although tungsten hexafluoride is used as the feedstock gas in the above case, it is also possible to use W(CO)[0081] 6 gas therefor.
  • Moreover, the present invention involves in its scope cases where barrier films are produced by using high temperature-melting point metals other than tungsten and forming thin films of the nitrides thereof. When titanium (Ti) is used as the high temperature-melting point metal, titanium halide gases (TiF[0082] 4, TiCl4, etc.) are usable as the feedstock gas. When tantalum (Ta) is used as the high temperature-melting point metal, tantalum halide gases (TaCl5, etc.) are usable as the feedstock gas. It is also possible to use halides of Mo or Nb as the feedstock gas.
  • As the reductive nitrogen-containing gas containing a nitrogen atom, use can be made of N[0083] 2H4 gas, NF3 gas, N 2 0 gas, etc. in addition to NH3 gas.
  • As the nitrogen-free auxiliary reductive gas, use can be made of H[0084] 2 gas, Si2H6 gas, PH3 gas, B2H6 gas etc. in addition to SiH4 gas.
  • As the diluent gas, it is also possible to use argon gas, nitrogen gas, helium gas or a mixture of these gases. [0085]
  • The cleaning conditions as described above are given merely by way of example. Therefore, the cleaning may be performed under different conditions. For example, similar effects can be achieved by carrying out the cleaning for 60 seconds at an argon gas flow rate of 100 sccm, under a pressure of 1.0 Pa at a high-frequency electric power of 150W. [0086]
  • After completing the cleaning under such conditions, additional cleaning may be performed by adding ammonia gas to the argon gas. [0087]
  • According to the present invention, a barrier film (a thin film of the nitride of a high temperature-melting point metal) having a low resistance can be formed by the CVD method at a temperature of 500° C. or lower, in particular, from 350 to 450° C. Therefore, interlayer insulation films are not damaged thereby. [0088]
  • Furthermore, the thin nitride film is formed by the heat CVD method, which makes it possible to achieve good step coverage. [0089]

Claims (10)

What is claimed is:
1. A process for producing a barrier film which comprises the steps of:
providing a substrate in a vacuum atmosphere;
introducing a feedstock gas having a high temperature-melting point metal in its structure and a reductive nitrogen-containing gas comprising a nitrogen atom into said vacuum atmosphere; and
forming a thin film of the nitride of said high temperature-melting point metal on said substrate;
wherein a nitrogen-free auxiliary reductive gas is introduced into said vacuum atmosphere.
2. The process for producing a barrier film according to claim 1, which comprises a step of introducing said auxiliary reductive gas together with said feedstock gas and said reductive nitrogen-containing gas into said vacuum atmosphere.
3. The process for producing a barrier film according to claim 2, which comprises a step of introducing said feedstock gas and said reductive nitrogen-containing gas into said vacuum atmosphere without introducing said auxiliary reductive gas.
4. The process for producing a barrier film according to claim 2, wherein, in the step of introducing said auxiliary reductive gas together with said reductive nitrogen-containing gas and said feedstock gas;
said reductive nitrogen-containing gas is introduced at a flow rate once or more higher than the flow rate of said feedstock gas, and said auxiliary reductive gas is introduced at a flow rate once or more but not more than 10 times higher than the flow rate of said reductive nitrogen-containing gas.
5. The process for producing a barrier film according to claim 1, wherein, in the step of introducing said auxiliary reductive gas together with said reductive nitrogen-containing gas and said feedstock gas;
said reductive nitrogen-containing gas is introduced at a flow rate once or more but not more than 5 times higher than the flow rate of said feedstock gas, and said auxiliary reductive gas is introduced at a flow rate 2 times or more but not more than 10 times higher than the flow rate of said reductive nitrogen-containing gas.
6. The process for producing a barrier film according to claim 2, wherein, in the step of introducing said auxiliary reductive gas together with said reductive nitrogen-containing gas and said feedstock gas;
said auxiliary reductive gas is introduced at a flow rate once or more but not more than 15 times higher than the flow rate of the feedstock gas having said high temperature-melting point metal.
7. The process for producing a barrier film according to claim 1, wherein, in the step of growing the thin film of the nitride of said high temperature-melting point metal;
a diluent gas not reacting with said high temperature-melting point metal and a gas having an oxygen atom in its chemical structure are introduced so that the pressure of said vacuum atmosphere is regulated to 1 Pa or more but not more than 100 Pa.
8. A process for producing a barrier film for forming a barrier film made of a thin film of the nitride of a high temperature-melting point metal on a substrate, wherein;
the surface of said substrate is exposed to a plasma of hydrogen gas and a plasma containing at least one gas selected from among argon, nitrogen and helium gases, and then the thin film of the nitride of said high temperature-melting point metal is formed on the surface of the substrate.
9. A barrier film comprising a thin nitride film of a high temperature-melting point metal, wherein;
said thin nitride film has a content of said high temperature-melting point metal exceeding the stoichiometric composition ratio thereof.
10. A barrier film comprising a thin nitride film of a high temperature-melting point metal formed on a substrate and aiming at preventing the diffusion of metals in an interconnecting thin film formed on said thin nitride film, wherein;
said thin nitride film is free from silicon.
US10/133,432 1999-02-17 2002-04-29 Process for producing barrier film and barrier film thus produced Abandoned US20020123215A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US10/133,432 US20020123215A1 (en) 1999-02-17 2002-04-29 Process for producing barrier film and barrier film thus produced

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JPHEI11-38041 1999-02-17
JP03804199A JP4009034B2 (en) 1999-02-17 1999-02-17 Barrier film manufacturing method
JPHEI11-192026 1999-07-06
JP19202699A JP3938450B2 (en) 1999-07-06 1999-07-06 Barrier film manufacturing method
US09/504,923 US6743718B1 (en) 1999-02-17 2000-02-16 Process for producing barrier film and barrier film thus produced
US10/133,432 US20020123215A1 (en) 1999-02-17 2002-04-29 Process for producing barrier film and barrier film thus produced

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US09/504,923 Division US6743718B1 (en) 1999-02-17 2000-02-16 Process for producing barrier film and barrier film thus produced

Publications (1)

Publication Number Publication Date
US20020123215A1 true US20020123215A1 (en) 2002-09-05

Family

ID=26377222

Family Applications (2)

Application Number Title Priority Date Filing Date
US09/504,923 Expired - Lifetime US6743718B1 (en) 1999-02-17 2000-02-16 Process for producing barrier film and barrier film thus produced
US10/133,432 Abandoned US20020123215A1 (en) 1999-02-17 2002-04-29 Process for producing barrier film and barrier film thus produced

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US09/504,923 Expired - Lifetime US6743718B1 (en) 1999-02-17 2000-02-16 Process for producing barrier film and barrier film thus produced

Country Status (5)

Country Link
US (2) US6743718B1 (en)
EP (1) EP1029943B1 (en)
KR (1) KR100773280B1 (en)
DE (1) DE60019660T2 (en)
TW (1) TW451357B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090152736A1 (en) * 2007-12-14 2009-06-18 Kabushiki Kaisha Toshiba Semiconductor device and method of fabricating the same

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1473761A1 (en) * 2003-05-02 2004-11-03 Air Products And Chemicals, Inc. Method for depositing metal films
US7311946B2 (en) 2003-05-02 2007-12-25 Air Products And Chemicals, Inc. Methods for depositing metal films on diffusion barrier layers by CVD or ALD processes
US20050085084A1 (en) * 2003-10-16 2005-04-21 Chang Edward Y. Method of fabricating copper metallization on backside of gallium arsenide devices
JP2007165788A (en) * 2005-12-16 2007-06-28 Tokyo Electron Ltd Decarbonization treatment method of metallic film, deposition method, and method for manufacturing semiconductor device
JP5145225B2 (en) * 2006-07-14 2013-02-13 株式会社アルバック Manufacturing method of semiconductor device
US20090032949A1 (en) * 2007-08-02 2009-02-05 Micron Technology, Inc. Method of depositing Tungsten using plasma-treated tungsten nitride

Citations (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5196360A (en) * 1990-10-02 1993-03-23 Micron Technologies, Inc. Methods for inhibiting outgrowth of silicide in self-aligned silicide process
US5487923A (en) * 1991-07-16 1996-01-30 Korea Institute Of Science And Technology Method for depositing tungsten nitride thin films for formation of metal wirings of silicon semiconductor elements
US5780908A (en) * 1995-05-09 1998-07-14 Matsushita Electric Industrial Co., Ltd. Semiconductor apparatus with tungstein nitride
US5801095A (en) * 1995-06-06 1998-09-01 Advanced Micro Devices, Inc. Production worthy interconnect process for deep sub-half micrometer back-end-of-line technology
US5861675A (en) * 1996-12-26 1999-01-19 Kabushiki Kaisha Toshiba Semiconductor device having WNF film and method of manufacturing such a device
US5893731A (en) * 1997-05-23 1999-04-13 Industrial Technology Research Institute Method for fabricating low cost integrated resistor capacitor combinations
US5895265A (en) * 1993-03-22 1999-04-20 Sanyo Electric Co., Ltd. Semiconductor device having cap-metal layer
US5919531A (en) * 1997-03-26 1999-07-06 Gelest, Inc. Tantalum and tantalum-based films and methods of making the same
US5923999A (en) * 1996-10-29 1999-07-13 International Business Machines Corporation Method of controlling dopant diffusion and metal contamination in thin polycide gate conductor of mosfet device
US5935648A (en) * 1997-03-28 1999-08-10 The United States Of America As Represented By The Secretary Of The Air Force High surface area molybdenum nitride electrodes
US5985753A (en) * 1998-08-19 1999-11-16 Advanced Micro Devices, Inc. Method to manufacture dual damascene using a phantom implant mask
US5990011A (en) * 1997-09-18 1999-11-23 Micron Technology, Inc. Titanium aluminum alloy wetting layer for improved aluminum filling of damescene trenches
US6025259A (en) * 1998-07-02 2000-02-15 Advanced Micro Devices, Inc. Dual damascene process using high selectivity boundary layers
US6054771A (en) * 1997-01-31 2000-04-25 Nec Corporation Interconnection system in a semiconductor device
US6090702A (en) * 1995-07-05 2000-07-18 Fujitsu Limited Embedded electroconductive layer and method for formation thereof
US6093638A (en) * 1998-12-10 2000-07-25 Texas Instruments Incorporated Method of forming an electrical contact in a substrate
US6100184A (en) * 1997-08-20 2000-08-08 Sematech, Inc. Method of making a dual damascene interconnect structure using low dielectric constant material for an inter-level dielectric layer
US6124635A (en) * 1997-03-21 2000-09-26 Honda Giken Kogyo Kabushiki Kaisha Functionally gradient integrated metal-ceramic member and semiconductor circuit substrate application thereof
US6140231A (en) * 1999-02-12 2000-10-31 Taiwan Semiconductor Manufacturing Company Robust diffusion barrier for Cu metallization
US6235632B1 (en) * 1998-01-13 2001-05-22 Advanced Micro Devices, Inc. Tungsten plug formation
US6282080B1 (en) * 1997-08-20 2001-08-28 Micron Technology, Inc. Semiconductor circuit components and capacitors
US20010046021A1 (en) * 1997-08-28 2001-11-29 Takeshi Kozuka A conductive particle to conductively bond conductive members to each other, an anisotropic adhesive containing the conductive particle, a liquid crystal display device using the anisotropic conductive adhesive, a method for manufacturing the liquid crystal display device
US6342417B2 (en) * 1999-02-16 2002-01-29 Micron Technology, Inc. Methods of forming materials comprising tungsten and nitrogen
US6399479B1 (en) * 1999-08-30 2002-06-04 Applied Materials, Inc. Processes to improve electroplating fill
US6495200B1 (en) * 1998-12-07 2002-12-17 Chartered Semiconductor Manufacturing Ltd. Method to deposit a seeding layer for electroless copper plating
US6503375B1 (en) * 2000-02-11 2003-01-07 Applied Materials, Inc Electroplating apparatus using a perforated phosphorus doped consumable anode
US6524953B1 (en) * 1998-02-19 2003-02-25 Micron Technology, Inc. Asymmetric, double-sided self-aligned silicide and method of forming the same
US6635570B1 (en) * 1999-09-30 2003-10-21 Carl J. Galewski PECVD and CVD processes for WNx deposition
US20030198587A1 (en) * 1999-02-12 2003-10-23 Gelest, Inc. Method for low-temperature organic chemical vapor deposition of tungsten nitride, tungsten nitride films and tungsten nitride diffusion barriers for computer interconnect metallization

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3522427A1 (en) * 1985-06-22 1986-02-20 Helmut Dipl Ing Fischer Titanium oxynitride layer for use in sensors
EP0536664B1 (en) * 1991-10-07 1997-01-15 Sumitomo Metal Industries, Ltd. A method for forming a thin film
JP3328358B2 (en) * 1993-03-26 2002-09-24 川崎マイクロエレクトロニクス株式会社 Method for manufacturing semiconductor device
US6251758B1 (en) * 1994-11-14 2001-06-26 Applied Materials, Inc. Construction of a film on a semiconductor wafer
AU4290396A (en) * 1994-11-30 1996-06-19 Micron Technology, Inc. A method of depositing tungsten nitride using a source gas comprising silicon
TW365685B (en) * 1996-10-31 1999-08-01 Texas Instruments Inc Low-temperature processes for depositing barrier films containing tungsten and nitrogen
US5989652A (en) * 1997-01-31 1999-11-23 Tokyo Electron Limited Method of low temperature plasma enhanced chemical vapor deposition of tin film over titanium for use in via level applications

Patent Citations (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5196360A (en) * 1990-10-02 1993-03-23 Micron Technologies, Inc. Methods for inhibiting outgrowth of silicide in self-aligned silicide process
US5487923A (en) * 1991-07-16 1996-01-30 Korea Institute Of Science And Technology Method for depositing tungsten nitride thin films for formation of metal wirings of silicon semiconductor elements
US5895265A (en) * 1993-03-22 1999-04-20 Sanyo Electric Co., Ltd. Semiconductor device having cap-metal layer
US5780908A (en) * 1995-05-09 1998-07-14 Matsushita Electric Industrial Co., Ltd. Semiconductor apparatus with tungstein nitride
US5801095A (en) * 1995-06-06 1998-09-01 Advanced Micro Devices, Inc. Production worthy interconnect process for deep sub-half micrometer back-end-of-line technology
US6090702A (en) * 1995-07-05 2000-07-18 Fujitsu Limited Embedded electroconductive layer and method for formation thereof
US5923999A (en) * 1996-10-29 1999-07-13 International Business Machines Corporation Method of controlling dopant diffusion and metal contamination in thin polycide gate conductor of mosfet device
US5861675A (en) * 1996-12-26 1999-01-19 Kabushiki Kaisha Toshiba Semiconductor device having WNF film and method of manufacturing such a device
US6054771A (en) * 1997-01-31 2000-04-25 Nec Corporation Interconnection system in a semiconductor device
US6124635A (en) * 1997-03-21 2000-09-26 Honda Giken Kogyo Kabushiki Kaisha Functionally gradient integrated metal-ceramic member and semiconductor circuit substrate application thereof
US5919531A (en) * 1997-03-26 1999-07-06 Gelest, Inc. Tantalum and tantalum-based films and methods of making the same
US5935648A (en) * 1997-03-28 1999-08-10 The United States Of America As Represented By The Secretary Of The Air Force High surface area molybdenum nitride electrodes
US5893731A (en) * 1997-05-23 1999-04-13 Industrial Technology Research Institute Method for fabricating low cost integrated resistor capacitor combinations
US6100184A (en) * 1997-08-20 2000-08-08 Sematech, Inc. Method of making a dual damascene interconnect structure using low dielectric constant material for an inter-level dielectric layer
US6282080B1 (en) * 1997-08-20 2001-08-28 Micron Technology, Inc. Semiconductor circuit components and capacitors
US20010046021A1 (en) * 1997-08-28 2001-11-29 Takeshi Kozuka A conductive particle to conductively bond conductive members to each other, an anisotropic adhesive containing the conductive particle, a liquid crystal display device using the anisotropic conductive adhesive, a method for manufacturing the liquid crystal display device
US5990011A (en) * 1997-09-18 1999-11-23 Micron Technology, Inc. Titanium aluminum alloy wetting layer for improved aluminum filling of damescene trenches
US6235632B1 (en) * 1998-01-13 2001-05-22 Advanced Micro Devices, Inc. Tungsten plug formation
US6524953B1 (en) * 1998-02-19 2003-02-25 Micron Technology, Inc. Asymmetric, double-sided self-aligned silicide and method of forming the same
US6025259A (en) * 1998-07-02 2000-02-15 Advanced Micro Devices, Inc. Dual damascene process using high selectivity boundary layers
US5985753A (en) * 1998-08-19 1999-11-16 Advanced Micro Devices, Inc. Method to manufacture dual damascene using a phantom implant mask
US6495200B1 (en) * 1998-12-07 2002-12-17 Chartered Semiconductor Manufacturing Ltd. Method to deposit a seeding layer for electroless copper plating
US6093638A (en) * 1998-12-10 2000-07-25 Texas Instruments Incorporated Method of forming an electrical contact in a substrate
US6140231A (en) * 1999-02-12 2000-10-31 Taiwan Semiconductor Manufacturing Company Robust diffusion barrier for Cu metallization
US20030198587A1 (en) * 1999-02-12 2003-10-23 Gelest, Inc. Method for low-temperature organic chemical vapor deposition of tungsten nitride, tungsten nitride films and tungsten nitride diffusion barriers for computer interconnect metallization
US6342417B2 (en) * 1999-02-16 2002-01-29 Micron Technology, Inc. Methods of forming materials comprising tungsten and nitrogen
US6399479B1 (en) * 1999-08-30 2002-06-04 Applied Materials, Inc. Processes to improve electroplating fill
US6635570B1 (en) * 1999-09-30 2003-10-21 Carl J. Galewski PECVD and CVD processes for WNx deposition
US6503375B1 (en) * 2000-02-11 2003-01-07 Applied Materials, Inc Electroplating apparatus using a perforated phosphorus doped consumable anode

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090152736A1 (en) * 2007-12-14 2009-06-18 Kabushiki Kaisha Toshiba Semiconductor device and method of fabricating the same
US8044519B2 (en) * 2007-12-14 2011-10-25 Kabushiki Kaisha Toshiba Semiconductor device and method of fabricating the same

Also Published As

Publication number Publication date
US6743718B1 (en) 2004-06-01
KR20000076639A (en) 2000-12-26
EP1029943B1 (en) 2005-04-27
DE60019660D1 (en) 2005-06-02
DE60019660T2 (en) 2006-01-19
KR100773280B1 (en) 2007-11-05
TW451357B (en) 2001-08-21
EP1029943A1 (en) 2000-08-23

Similar Documents

Publication Publication Date Title
US6399490B1 (en) Highly conformal titanium nitride deposition process for high aspect ratio structures
US6955986B2 (en) Atomic layer deposition methods for forming a multi-layer adhesion-barrier layer for integrated circuits
US6955983B2 (en) Methods of forming metal interconnections of semiconductor devices by treating a barrier metal layer
US6139700A (en) Method of and apparatus for forming a metal interconnection in the contact hole of a semiconductor device
US7244683B2 (en) Integration of ALD/CVD barriers with porous low k materials
EP1192292B1 (en) Plasma treatment of thermal cvd tan films from tantalum halide precursors
EP1185722B1 (en) Pecvd of tan films from tantalum halide precursors
US5972179A (en) Silicon IC contacts using composite TiN barrier layer
US6475912B1 (en) Semiconductor device and method and apparatus for fabricating the same while minimizing operating failures and optimizing yield
US7799674B2 (en) Ruthenium alloy film for copper interconnects
US6218301B1 (en) Deposition of tungsten films from W(CO)6
US7484513B2 (en) Method of forming titanium film by CVD
US20030059980A1 (en) Copper interconnect barrier layer structure and formation method
US20020114886A1 (en) Method of tisin deposition using a chemical vapor deposition process
US20040235191A1 (en) Film forming method
CN101174577A (en) Integration of ald tantalum nitride and alpha-phase tantalum for copper metallization application
Elers et al. Atomic layer deposition of WxN/TiN and WNxCy/TiN nanolaminates
US20020132469A1 (en) Method for forming metal wiring layer
CN1319146C (en) Integration of ald tantalum nitride and alpha-phase tantalum for copper metallization application
EP1029943B1 (en) Process for producing barrier film
JP3938450B2 (en) Barrier film manufacturing method
US6635570B1 (en) PECVD and CVD processes for WNx deposition
JP4009034B2 (en) Barrier film manufacturing method
TWI283006B (en) Method for forming tungsten nitride film
US6787466B2 (en) High throughout process for the formation of a refractory metal nucleation layer

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION