Methods for ALD of Metal Oxides on Metal Surfaces

Abstract

Methods for depositing metal oxide layers on metal surfaces are described. The methods include exposing a substrate to separate doses of a metal precursor, which does not contain metal-oxygen bonds, and an alcohol. These methods do not oxidize the underlying metal layer.

What is claimed is: 
     
         1 . A deposition method comprising exposing a substrate with a first metal surface separately to a second metal precursor and an alcohol to form a second metal oxide layer on the first metal surface. 
     
     
         2 . The method of  claim 1 , wherein the first metal comprises one or more of cobalt, copper, nickel, ruthenium, tungsten, or platinum. 
     
     
         3 . The method of  claim 2 , wherein the first metal consists essentially of cobalt. 
     
     
         4 . The method of  claim 2 , wherein the first metal consists essentially of copper. 
     
     
         5 . The method of  claim 1 , wherein the second metal comprises on or more of aluminum, hafnium, zirconium, nickel, zinc, tantalum or titanium. 
     
     
         6 . The method of  claim 1 , wherein the second metal precursor comprises substantially no metal-oxygen bonds. 
     
     
         7 . The method of  claim 1 , wherein the second metal consists essentially of aluminum. 
     
     
         8 . The method of  claim 1 , wherein the second metal precursor comprises at least one carbo ligand. 
     
     
         9 . The method of  claim 8 , wherein the second metal precursor comprises only carbo ligands. 
     
     
         10 . The method of  claim 8 , wherein the at least one carbo ligand contains 1 to 6 carbon atoms. 
     
     
         11 . The method of  claim 10 , wherein the carbo ligand is methyl or ethyl. 
     
     
         12 . The method of  claim 8 , wherein the second metal oxide layer contains substantially no carbon. 
     
     
         13 . The method of  claim 1 , wherein the second metal precursor comprises at least one amino ligand. 
     
     
         14 . The method of  claim 1 , wherein the second metal precursor comprises at least one halide ligand. 
     
     
         15 . The method of  claim 1 , wherein the method produces substantially no oxidation on the first metal surface. 
     
     
         16 . The method of  claim 1 , further comprising cleaning the substrate before exposing the substrate to form the second metal oxide layer. 
     
     
         17 . The method of  claim 16 , wherein cleaning the substrate comprises exposing the substrate to a hydrogen plasma. 
     
     
         18 . The method of  claim 1 , wherein the alcohol contains 1 to 10 carbon atoms. 
     
     
         19 . The method of  claim 18 , wherein the alcohol consists essentially of methanol, ethanol, isopropanol, or t-butanol. 
     
     
         20 . The method of  claim 1 , wherein the substrate is maintained at a temperature less than or equal to about 350° C.