Gap fill methods using catalyzed deposition

Abstract

Methods of depositing a metal film are discussed. A metal film is formed on the bottom of feature having a metal bottom and dielectric sidewalls. Formation of the metal film comprises exposure to a metal precursor and an alkyl halide catalyst while the substrate is maintained at a deposition temperature. The metal precursor has a decomposition temperature above the deposition temperature. The alkyl halide comprises carbon and halogen, and the halogen comprises bromine or iodine.

What is claimed is: 
     
         1 . A metal deposition method comprising sequentially exposing a substrate having at least one feature comprising a bottom and sidewalls to a metal precursor and an alkyl halide catalyst while the substrate is maintained at a deposition temperature to form a metal film on the bottom of the feature, the bottom of the feature comprising a first metal and the sidewalls of the feature comprising a dielectric, the metal precursor having a decomposition temperature above the deposition temperature, and the alkyl halide comprising carbon and halogen, and the halogen comprising bromine or iodine. 
     
     
         2 . The method of  claim 1 , wherein the first metal at the bottom of the feature comprises one or more of molybdenum, ruthenium, cobalt, copper, platinum, nickel or tungsten. 
     
     
         3 . The method of  claim 1 , wherein the metal film comprises one or more of tungsten, ruthenium, molybdenum or copper. 
     
     
         4 . The method of  claim 1 , wherein the metal precursor comprises a metal atom bonded to one or more of an optionally alkyl substituted benzene ring and an open or closed diene. 
     
     
         5 . The method of  claim 1 , wherein the alkyl halide consists essentially of iodoethane or diiodomethane. 
     
     
         6 . The method of  claim 1 , wherein the metal film is formed selectively on the bottom of the feature relative to the sidewalls. 
     
     
         7 . The method of  claim 1 , wherein the metal film fills the feature in a bottom-up manner to form a seam-free gap fill. 
     
     
         8 . The method of  claim 7 , wherein the seam-free gap fill is formed without a liner between the metal film and the sidewalls. 
     
     
         9 . The method of  claim 1 , wherein the metal precursor and the alkyl halide catalyst are exposed to the substrate together. 
     
     
         10 . The method of  claim 1 , wherein the metal precursor and the alkyl halide catalyst are exposed to the substrate separately and sequentially in a cycle. 
     
     
         11 . The method of  claim 10 , wherein the alkyl halide catalyst is exposed to the substrate prior to the metal precursor exposure to form a catalyst layer on the metal bottom of the feature. 
     
     
         12 . The method of  claim 11 , further comprising exposing the substrate with the catalyst layer on the metal bottom of the feature to an anisotropic etch to remove any catalyst from the dielectric. 
     
     
         13 . The method of  claim 11 , wherein the metal film has a growth rate greater than or equal to about 0.8 Å/cycle. 
     
     
         14 . The method of  claim 1 , further comprising cleaning the first metal at the bottom of the feature to remove oxides from the first metal prior to exposure to the metal precursor and alkyl halide catalyst.