Methods for forming impurity free metal alloy films

Abstract

Methods of depositing a metal film by exposing a substrate surface to a halide precursor and an organosilane reactant are described. The halide precursor comprises a compound of general formula (I): MQ z R m , wherein M is a metal, Q is a halogen selected from Cl, Br, F or I, z is from 1 to 6, R is selected from alkyl, CO, and cyclopentadienyl, and m is from 0 to 6. The aluminum reactant comprises a compound of general formula (II) or general formula (III): wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R a , R b , R c , R d , R e , and R f are independently selected from hydrogen (H), substituted alkyl or unsubstituted alkyl; and X, Y, X′, and Y′ are independently selected from nitrogen (N) and carbon (C).

What is claimed is: 
     
         1 . A non-transitory computer readable medium including instructions, that, when executed by a controller of a processing chamber, causes the processing chamber to perform operations of:
 flow a first halide precursor into a processing volume of the processing chamber having a substrate, the first halide precursor having general Formula (I)
   MQ z R m   (I),
 
 wherein M is a metal comprising titanium (Ti), Q is a halogen selected from Cl, Br, F or I, z is from 1 to 6, R is selected from alkyl, CO, cyclopentadienyl, amidinate, diazadiene, or amidate, and m is from 0 to 6, 
   purge the processing chamber of the first halide precursor;   expose the substrate to an organosilane precursor of general Formula (III):   
       
         
           
           
               
               
           
         
         
           wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R a , R b , R c , R d , R e , and R f  are independently selected from hydrogen (H), substituted alkyl or unsubstituted alkyl; and X, Y, X′, and Y′ are independently selected from nitrogen (N) and carbon (C): 
         
         purge the processing chamber of the organosilane precursor; 
         flow a second halide precursor into a processing volume of the processing chamber having a substrate, the second halide precursor; 
         purge the processing chamber of the second halide precursor aluminum chloride (AlCl 3 ); 
         expose the substrate to the organosilane precursor of general Formula (III); and 
         purge the processing chamber of the organosilane precursor. 
       
     
     
         2 . The non-transitory computer readable medium of  claim 1 , wherein Q is Cl or Br. 
     
     
         3 . The non-transitory computer readable medium of  claim 1 , wherein Q is Cl. 
     
     
         4 . The non-transitory computer readable medium of  claim 1 , wherein at least one of R a , R b , R c , R d , R c , and R f  comprises methyl. 
     
     
         5 . The non-transitory computer readable medium of  claim 1 , wherein exposing the substrate surface to the first halide precursor and the organosilane reactant occurs sequentially. 
     
     
         6 . The non-transitory computer readable medium of  claim 1 , wherein exposing the substrate surface to the first halide precursor and the organosilane reactant occurs simultaneously. 
     
     
         7 . The non-transitory computer readable medium of  claim 1 , wherein the substrate is in a processing chamber. 
     
     
         8 . The non-transitory computer readable medium of  claim 7 , further comprising purging the processing chamber of each of the first halide precursor and the second halide precursor prior to exposing the substrate to the organosilane reactant. 
     
     
         9 . The non-transitory computer readable medium of  claim 8 , further comprising purging the processing chamber of the organosilane reactant. 
     
     
         10 . The non-transitory computer readable medium of  claim 1 , wherein m is from 1 to 6. 
     
     
         11 . A gate stack comprising:
 a high-κ dielectric layer on a substrate;   a first titanium nitride layer on the high-κ dielectric layer;   a work-function layer on the first titanium nitride layer; and   a second titanium nitride layer on the work-function layer,   wherein the work-function layer comprises a metal film having more than one metal M, the metal film substantially free of carbon.   
     
     
         12 . The gate stack of  claim 11 , wherein the metal film comprises one or more of titanium (Ti) and aluminum (Al). 
     
     
         13 . The gate stack of  claim 11 , wherein the work function layer comprises titanium aluminum carbide (TiAlC).