Apparatus and concept for minimizing parasitic chemical vapor deposition during atomic layer deposition

Abstract

A new method and apparatus for avoiding contamination of films deposited in layered depositions, such as Atomic Layer Deposition (ALD) and other sequential chemical vapor deposition (CVD) processes, is taught, wherein CVD-deposited contamination of ALD films is prevented by use of a pre-reaction chamber that effectively causes otherwise-contaminating gaseous constituents to deposit on wall elements of gas-delivery apparatus prior to entering the ALD chamber.

What is claimed is:  
     
         1 . A method for minimizing parasitic chemical vapor deposition during an atomic layer deposition process, comprising steps of: 
 (a) imposing a pre-reaction chamber between gas sources and a substrate to be coated; and    (b) heating a surface in the pre-reaction chamber to a temperature sufficient to cause contaminant elements to deposit by CVD reaction on the heated surface.    
     
     
         2 . A pre-reaction chamber for an atomic layer deposition system, comprising; 
 a passage for delivery of gases in alternating, incremental fashion from a gas source to a gas distribution apparatus; and    a heated surface within the pre-reaction chamber for causing contaminant elements to deposit prior to the gases entering the gas distribution apparatus.