Atomic layer deposition of noble metals

Abstract

The present invention relates to ALD processes for deposition of a metal selected from Pd, Rh, Ru, Pt and Ir wherein a layer including the metal is formed on a surface composed of a material selected from W, Ta, Cu, Ni, Co, Fe, Mn, Cr, V Nb, tungsten nitride, tantalum nitride, titanium nitride, dielectrics and activated dielectrics at a temperature ranging from >60° C. to <260° C. The layer is formed by sequentially pulsing into a chamber containing the surface a precursor for the metal and a reducing gas selected from hydrogen, glyoxylic acid, oxalic acid, formaldehyde, 2-propanol, imidazole and plasma-activated hydrogen.

1 . An ALD process for deposition of a metal selected from Pd, Rh, Ru, Pt and Ir comprising forming a layer comprising the metal on a surface comprising a material selected from W, Ta, Cu, Ni, Co, Fe, Mn, Cr, V Nb, tungsten nitride, tantalum nitride, titanium nitride, dielectrics and activated dielectrics at a temperature ranging from >60° C. to <260° C.  
     
     
         2 . An ALD process according to  claim 1 , wherein forming a layer comprises sequentially pulsing into a chamber containing the surface a precursor for the metal and a reducing gas selected from hydrogen, glyoxylic acid, oxalic acid, formaldehyde, 2-propanol, imidazole and plasma-activated hydrogen.  
     
     
         3 . An ALD process for deposition of a metal selected from Pd, Rh, Ru, Pt and Ir comprising 
 providing a surface comprising a material selected from noble metals, W, Ta, TaN, tungsten nitride, tantalum nitride, titanium nitride, Cu, Ni, Co, Fe, Mn, Cr, V and Nb in a reaction chamber;    pulsing a precursor for the metal into the chamber at a temperature ranging from >60° C. to <260° C.; and    pulsing hydrogen gas into the chamber.    
     
     
         4 . An ALD process according to  claim 3  wherein the surface is a noble metal.  
     
     
         5 . An ALD process according to  claim 3  wherein the surface is a pretreated metallic surface selected from W, Ta, tungsten nitride, tantalum nitride, and titanium nitride.  
     
     
         6 . An ALD process according to  claim 3  wherein the surface is a metal selected from Cu, Ni, Co, Fe, Mn, Cr, V and Nb.  
     
     
         7 . An ALD process for deposition of a metal selected from Pd, Rh, Ru, Pt and Ir comprising 
 providing a surface comprising a material selected from noble metals, W, Ta, Cu, Ni, Co, Fe, Mn, Cr, V Nb, tungsten nitride, tantalum nitride, titanium nitride, dielectrics and activated dielectrics in a reaction chamber at a temperature ranging from >60° C. to <260° C.;    pulsing a precursor for the metal into the chamber; and    pulsing into the chamber a reducing gas selected from glyoxylic acid, oxalic acid, formaldehyde, 2-propanol, and imidazole.    
     
     
         8 . An ALD process according to  claim 7  wherein the reducing gas is glyoxylic acid.  
     
     
         9 . An ALD process according to  claim 7  wherein the activated dielectric surface comprises at least one of thiol, sulfide, tetrasulfide, phosphine, phosphide or amine groups.  
     
     
         10 . An ALD process according to  claim 7  wherein the activated dielectric surface comprises thiol groups.  
     
     
         11 . An ALD process according to  claim 7  wherein the dielectric is selected from CVD polymers, organic-inorganic hybrids, and silicon or metals having an oxide-terminated surface.  
     
     
         12 . An ALD process for deposition of a metal selected from Pd, Rh, Ru, Pt and Ir comprising 
 providing a substrate in a reaction chamber;    pulsing a precursor for the metal into the chamber at a temperature ranging from >60° C. to <260° C.; and    pulsing plasma-activated hydrogen gas into the chamber.    
     
     
         13 . An ALD process according to  claim 1 , wherein the precursor is a metal β-diketonate compound.  
     
     
         14 . An ALD process according to  claim 1 , wherein the precursor is a metal-hfac compound.  
     
     
         15 . An ALD process according to  claim 1 , wherein the precursor is selected from Pd(hfac) 2 , Ru(hfac) 2 , Rh(hfac) 2 , Pt(hfac) 2 , Ir(hfac) 2 , Ir(acac) 2 , Pd(tmhd) 2 , Ru(tmhd) 2 , Rh(tmhd) 2 , Pt(tmhd) 2 , and Ir(tmhd) 2 .  
     
     
         16 . An ALD process according to  claim 1 , wherein the metal is Pd.  
     
     
         17 . An ALD process according to  claim 1 , wherein the precursor is Pd(hfac) 2 .