Methods For Depositing Metal Films On Diffusion Barrier Layers By CVD Processes

Abstract

A process is described for depositing a metal film on a substrate surface having a diffusion barrier layer deposited thereupon. In one embodiment of the present invention, the process includes: providing a surface of the diffusion barrier layer that is substantially free of an elemental metal and forming the metal film on at least a portion of the surface via deposition by using a organometallic precursor. In certain embodiments, the diffusion barrier layer may be exposed to an adhesion promoting agent prior to or during at least a portion of the forming step. Suitable adhesion promoting agents include nitrogen, nitrogen-containing compounds, carbon-containing compounds, carbon and nitrogen containing compounds, silicon-containing compounds, silicon and carbon containing compounds, silicon, carbon, and nitrogen containing compounds, or mixtures thereof. The process of the present invention provides substrates having enhanced adhesion between the diffusion barrier layer and the metal film.

1 . A process for forming a metal film on an at least one surface of a diffusion barrier layer, the process consisting of: 
 providing the at least one surface of the diffusion barrier layer comprising at least one material selected from the group consisting of a metal carbide, a metal nitride, a metal carbonitride, a metal silicon carbide, a metal silicon nitride, a metal silicon carbonitride, and mixtures therefrom, and wherein the diffusion barrier layer has an orientation of at least 95% substantially (111) preferred orientation; and    forming the metal film on at least a portion of the surface by a chemical vapor deposition process with at least one organometallic precursor, wherein the organometallic precursor comprises a metal selected from the group consisting of copper, platinum, nickel, cobalt, palladium, ruthenium, rhodium, irridium, gold, and silver.    
     
     
         2 . The process of  claim 1  wherein the chemical vapor deposition process is at least one process selected from the group consisting of thermal chemical vapor deposition, plasma enhanced chemical vapor deposition, remote plasma enhanced chemical vapor deposition, plasma assisted chemical vapor deposition, cryogenic chemical vapor deposition, chemical assisted vapor deposition, hot-filament chemical vapor deposition, photo-initiated chemical vapor deposition, or combinations thereof.  
     
     
         3 . The process of  claim 1  wherein the diffusion barrier layer is a metal nitride selected from the group consisting of chromium nitride, tantalum nitride, titanium nitride, tungsten nitride, molybdenum nitride, zirconium nitride, vanadium nitride, and mixtures thereof.  
     
     
         4 . The process of  claim 3  wherein the metal nitride is selected from the group consisting of tantalum nitride, titanium nitride, and tungsten nitride.  
     
     
         5 . The process of  claim 4  wherein the metal nitride is tantalum nitride.  
     
     
         6 . The process of  claim 1  wherein said diffusion barrier layer is a metal carbide selected from the group consisting of chromium carbide, tantalum carbide, titanium carbide, tungsten carbide, molybdenum carbide, zirconium carbide, vanadium carbide, and mixtures thereof.  
     
     
         7 . The process of  claim 1  wherein said diffusion barrier layer is a metal carbonitride selected from the group consisting of chromium carbonitride, tantalum carbonitride, titanium carbonitride, tungsten carbonitride, molybdenum carbonitride, zirconium carbonitride, vanadium carbonitride, and mixtures thereof.  
     
     
         8 . The process of  claim 1  wherein said diffusion barrier layer is a metal silicon nitride selected from the group consisting of tantalum silicon nitride, titanium silicon nitride, molybdenum silicon nitride, and mixtures thereof.  
     
     
         9 . The process of  claim 1  wherein said diffusion barrier layer is a metal silicon carbide selected from the group consisting of tantalum silicon carbide, titanium silicon carbide, and mixtures thereof.  
     
     
         10 . The process of  claim 1  wherein said diffusion barrier layer is a metal silicon carbonitride selected from the group consisting of silicon carbonitride, titanium silicon carbonitride, tantalum silicon carbonitride, and mixtures thereof.  
     
     
         11 . The process of  claim 1  wherein said organometallic precursor is non-fluorinated.  
     
     
         12 . The process of  claim 1  wherein said organometallic precursor is fluorinated.  
     
     
         13 . The process of  claim 12  wherein said organometallic precursor comprises hexafluoroacetylacetonate.  
     
     
         14 . The process of  claim 1  wherein said organometallic precursor comprises an organometallic copper precursor.  
     
     
         15 . The process of  claim 14  wherein said organometallic copper precursor is 1,1,1,5,5,5-hexafluoro-2,4-pentanedionato-copper (I) trimethylvinylsilane.  
     
     
         16 . The process of  claim 1  wherein said organometallic precursor is a compound represented by the following structure (I):  
       
         
           
           
               
               
           
         
         wherein M and M′ are each Cu, Ag, Au, Ir, Ru, Rh, or Re;  
         X and X′ are each N or O;  
         Y and Y′ are each Si, C, Sn, Ge, B, or Al;  
         Z and Z′ are each C, N, or O; R1, R2, R1′, and R2′ are each independently a hydrogen, an alkyl, an alkenyl, an alkynyl, a partially fluorinated alkyl, an aryl, an alkyl-substituted aryl, a partially fluorinated aryl, a fluoroalkyl-substituted aryl, a trialkylsilyl, or a triarylsilyl when X and X′ are N;  
         R1 and R1′ are each independently an alkyl, an alkenyl, an alkynyl, a partially fluorinated alkyl, an aryl, an alkyl-substituted aryl, a partially fluorinated aryl, a fluoroalkyl-substituted aryl, a trialkylsilyl, or a triarylsilyl when X and X′ are O;  
         R3, R4, R3′, and R4′ are each independently a hydrogen, an alkyl, a partially fluorinated alkyl, a trialkylsilyl, a triarylsilyl, a trialkylsiloxy, a triarylsiloxy, an aryl, an alkyl-substituted aryl, a partially fluorinated aryl, a fluoroalkyl-substituted aryl, or an alkoxy; and  
         R5, R6, R5′, and R6′ are each independently a hydrogen, an alkyl, an alkenyl, an alkynyl, a partially fluorinated alkyl, an aryl, an alkyl-substituted aryl, a partially fluorinated aryl, a fluoroalkyl-substituted aryl, a trialkylsiloxy, a triarylsiloxy, a trialkylsilyl, a triarylsilyl, or an alkoxy;  
         provided that when X and X′ are each 0, there is no substitution at R2 and R2′;  
         further provided that when Z and Z′ are each N, there is no substitution at R6 and R6′;  
         further provided that when Z and Z′ are each 0, there is no substitution at R5, R6, R5′, or R6′;  
         said alkyl and alkoxide having 1 to 8 carbons; said alkenyl and alkynyl having 2 to 8 carbons; and said aryl having 6 carbons.  
       
     
     
         17 . The process of  claim 1  wherein the metal film comprises at least one metal selected from the group consisting of copper, platinum, cobalt, nickel, palladium, ruthenium, rhodium, iridium, gold, silver, and mixtures thereof.  
     
     
         18 . A process for forming a metal film on an at least one surface of a diffusion barrier layer, the process consisting of: 
 providing the at least one surface of the diffusion barrier layer, wherein the diffusion barrier layer comprises at least one material selected from the group consisting of a metal, a metal carbide, a metal nitride, a metal carbonitride, a metal silicon carbide, a metal silicon nitride, a metal silicon carbonitride, and mixtures thereof, wherein the diffusion barrier layer is not substantially free of elemental metal because either (i) the at least one material is the metal, (ii) the diffusion barrier layer has an orientation other than a substantially (111) preferred orientation, or (iii) the diffusion barrier layer has less than 95% of a (111) preferred orientation;    exposing the at least one surface of the diffusion barrier layer to an at least one adhesion promoting agent selected from the group consisting of a nitrogen, a nitrogen-containing compound, a carbon-containing compound, a carbon and nitrogen containing compound, a silicon-containing compound, a silicon and carbon containing compound, a silicon, carbon, and nitrogen containing compound or a mixture thereof, is conducted at a temperature of from 40° C. to 400° C. such that the at least one surface becomes substantially free of an elemental metal; and    forming the metal film on at least a portion of the surface using an at least one organometallic precursor by a chemical vapor deposition process.    
     
     
         19 . The process of  claim 18  wherein the exposing step includes plasma activation.  
     
     
         20 . The process of  claim 18  wherein the exposing step is conducted prior to the forming step.  
     
     
         21 . The process of  claim 18  wherein the exposing step is conducted during at least a portion of the forming step.  
     
     
         22 . The process of  claim 18  wherein the chemical vapor deposition is at least one process selected from the group consisting of thermal chemical vapor deposition, plasma enhanced chemical vapor deposition, remote plasma enhanced chemical vapor deposition, plasma assisted chemical vapor deposition, cryogenic chemical vapor deposition, chemical assisted vapor deposition, hot-filament chemical vapor deposition, photo-initiated chemical vapor deposition, or combinations thereof.  
     
     
         23 . The process of  claim 18  wherein the diffusion barrier layer is a metal nitride selected from the group consisting of chromium nitride, tantalum nitride, titanium nitride, tungsten nitride, molybdenum nitride, zirconium nitride, vanadium nitride, and mixtures thereof.  
     
     
         24 . The process of  claim 23  wherein the metal nitride is selected from the group consisting of tantalum nitride, titanium nitride, and tungsten nitride.  
     
     
         25 . The process of  claim 24  wherein the metal nitride is tantalum nitride.  
     
     
         26 . The process of  claim 18  wherein said diffusion barrier layer is a metal carbide selected from the group consisting of chromium carbide, tantalum carbide, titanium carbide, tungsten carbide, molybdenum carbide, zirconium carbide, vanadium carbide, and mixtures thereof.  
     
     
         27 . The process of  claim 18  wherein said diffusion barrier layer is a metal carbonitride selected from the group consisting of chromium carbonitride, tantalum carbonitride, titanium carbonitride, tungsten carbonitride, molybdenum carbonitride, zirconium carbonitride, vanadium carbonitride, and mixtures thereof.  
     
     
         28 . The process of  claim 18  wherein said diffusion barrier layer is a metal silicon nitride selected from the group consisting of tantalum silicon nitride, titanium silicon nitride, molybdenum silicon nitride, and mixtures thereof.  
     
     
         29 . The process of  claim 18  wherein said diffusion barrier layer is a metal silicon carbide selected from the group consisting of tantalum silicon carbide, titanium silicon carbide, and mixtures thereof.  
     
     
         30 . The process of  claim 18  wherein said diffusion barrier layer is a metal silicon carbonitride selected from the group consisting of silicon carbonitride, titanium silicon carbonitride, tantalum silicon carbonitride, and mixtures thereof.  
     
     
         31 . The process of  claim 18  wherein said organometallic precursor is non-fluorinated.  
     
     
         32 . The process of  claim 18  wherein said organometallic precursor is fluorinated.  
     
     
         33 . The process of  claim 32  wherein said organometallic precursor comprises hexafluoroacetylacetonate.  
     
     
         34 . The process of  claim 18  wherein said organometallic precursor comprises an organometallic copper precursor.  
     
     
         35 . The process of  claim 34  wherein said organometallic copper precursor is 1,1,1,5,5,5-hexafluoro-2,4-pentanedionato-copper (I) trimethylvinylsilane.  
     
     
         36 . The process of  claim 18  wherein said organometallic precursor is a compound represented by the following structure (I):  
       
         
           
           
               
               
           
         
         wherein M and M′ are each Cu, Ag, Au, Ir, Ru, Rh, or Re;  
         X and X′ are each N or O;  
         Y and Y′ are each Si, C, Sn, Ge, B, or Al;  
         Z and Z′ are each C, N, or O; R1, R2, R1′, and R2′ are each independently a hydrogen, an alkyl, an alkenyl, an alkynyl, a partially fluorinated alkyl, an aryl, an alkyl-substituted aryl, a partially fluorinated aryl, a fluoroalkyl-substituted aryl, a trialkylsilyl, or a triarylsilyl when X and X′ are N;  
         R1 and R1′ are each independently an alkyl, an alkenyl, an alkynyl, a partially fluorinated alkyl, an aryl, an alkyl-substituted aryl, a partially fluorinated aryl, a fluoroalkyl-substituted aryl, a trialkylsilyl, or a triarylsilyl when X and X′ are O;  
         R3, R4, R3′, and R4′ are each independently a hydrogen, an alkyl, a partially fluorinated alkyl, a trialkylsilyl, a triarylsilyl, a trialkylsiloxy, a triarylsiloxy, an aryl, an alkyl-substituted aryl, a partially fluorinated aryl, a fluoroalkyl-substituted aryl, or an alkoxy; and  
         R5, R6, R5′, and R6′ are each independently a hydrogen, an alkyl, an alkenyl, an alkynyl, a partially fluorinated alkyl, an aryl, an alkyl-substituted aryl, a partially fluorinated aryl, a fluoroalkyl-substituted aryl, a trialkylsiloxy, a triarylsiloxy, a trialkylsilyl, a triarylsilyl, or an alkoxy;  
         provided that when X and X′ are each O, there is no substitution at R2 and R2′;  
         further provided that when Z and Z′ are each N, there is no substitution at R6 and R6′;  
         further provided that when Z and Z′ are each O, there is no substitution at R5, R6, R5′, or R6′;  
         said alkyl and alkoxide having 1 to 8 carbons; said alkenyl and alkynyl having 2 to 8 carbons; and said aryl having 6 carbons.