Vapor deposition of thin films comprising gold

Abstract

Vapor deposition processes for forming thin films comprising gold on a substrate in a reaction space are provided. The processes can be cyclical vapor deposition processes, such as atomic layer deposition (ALD) processes. The processes can include contacting the substrate with a gold precursor comprising at least one sulfur donor ligand and at least one alkyl ligand, and contacting the substrate with a second reactant comprising ozone. The deposited thin films comprising gold can be uniform, continuous, and conductive at very low thicknesses.

What is claimed is: 
     
         1 . A process for forming a thin film comprising gold on a substrate in a reaction space, the process comprising:
 sequentially contacting the substrate with a vapor phase organometallic gold precursor and a vapor phase second reactant,   wherein the gold precursor and the second reactant react to form the thin film comprising gold, and   wherein the thin film comprising gold has a step coverage of greater than 50%.   
     
     
         2 . The process of  claim 1 , wherein sequentially contacting the substrate with a vapor phase organometallic gold precursor and a vapor phase second reactant comprises a deposition cycle that is repeated two or more times. 
     
     
         3 . The process of  claim 2 , wherein the deposition cycle further comprises removing excess vapor phase organometallic gold precursor from the reaction space after contacting the substrate with the vapor phase gold precursor and prior to contacting the substrate with the vapor phase second reactant. 
     
     
         4 . The process of  claim 2 , wherein the deposition cycle further comprises removing excess vapor phase second reactant and reaction byproducts, if any, from the reaction space after contacting the substrate with the vapor phase second reactant. 
     
     
         5 . The process of  claim 2 , wherein the thin film comprising gold is deposited at a growth rate of more than about 0.8 Å per deposition cycle. 
     
     
         6 . The process of  claim 2 , wherein the deposition cycle is repeated until the thin film comprising gold has a thickness of from about 20 nm to about 50 nm. 
     
     
         7 . The process of  claim 2 , wherein the process is an atomic layer deposition (ALD) process. 
     
     
         8 . The process of  claim 2 , wherein the thin film comprising gold is continuous after 100 deposition cycles. 
     
     
         9 . The process of  claim 1 , wherein the gold of the organometallic gold precursor has an oxidation state of +III. 
     
     
         10 . The process of  claim 1 , wherein the organometallic gold precursor comprises at least one alkyl ligand. 
     
     
         11 . The process of  claim 1 , wherein the organometallic gold precursor comprises one or more neutral adducts. 
     
     
         12 . The process of  claim 1 , wherein the organometallic gold precursor comprises a ligand comprising sulfur or selenium. 
     
     
         13 . The process of  claim 1 , wherein the organometallic gold precursor comprises a diethyldithiocarbamato ligand. 
     
     
         14 . The process of  claim 13 , wherein the organometallic gold precursor comprises Me 2 Au(S 2 CNEt 2 ). 
     
     
         15 . The process of  claim 1 , wherein the vapor phase second reactant comprises oxygen. 
     
     
         16 . The process of  claim 15 , wherein the vapor phase second reactant comprises a reactive species of oxygen. 
     
     
         17 . The process of  claim 16 , wherein the vapor phase second reactant comprises ozone. 
     
     
         18 . The process of  claim 1 , wherein the process is carried out at a deposition temperature of from about 120° C. to about 220° C. 
     
     
         19 . The process of  claim 1 , wherein the substrate comprises a three-dimensional structure having an aspect ratio of more than 2. 
     
     
         20 . The process of  claim 1 , wherein the thin film comprising gold has a resistivity of less than about 20 μΩcm.