process tool including plasma spray for carbon nanotube growth

Abstract

This invention provides a high volume manufacturing compatible process tool and method for integrating deposition of carbon nanotubes into device fabrication. A linear process tool for growing carbon nanotubes comprises a linear conveyor for moving a substrate through the linear process tool and a micro-plasma process unit including a plurality of micro-plasma spray guns arranged in an array, the micro-plasma process unit being positioned above the linear conveyor and configured to deposit material on the surface of the substrate as the substrate passes under the micro-plasma process unit on the linear conveyor. The micro-plasma process unit may include a first array of micro-plasma spray guns for depositing a catalyst material and a second array of micro-plasma spray guns for depositing the carbon nanotubes. A method of depositing carbon nanotubes on a substrate comprises: supplying a first precursor for a catalyst material to a first array of micro-plasma spray guns; creating a first plasma using the first array of micro-plasma spray guns and the first precursor; moving the substrate through the first plasma; activating the catalyst material; supplying a second precursor for the carbon nanotubes to a second array of micro-plasma spray guns; creating a second plasma using the second array of micro-plasma spray guns and the second precursor; moving the substrate through the second plasma.

1 . A linear process tool for growing carbon nanotubes comprising:
 a linear conveyor for moving a substrate through said linear process tool;   a micro-plasma process unit including a plurality of micro-plasma spray guns arranged in an array, said process unit being positioned above said linear conveyor and configured to deposit material on the surface of said substrate as said substrate passes under said micro-plasma process unit on said linear conveyor; and   a heating unit configured to heat the surface of said substrate as said substrate passes under said heating unit on said linear conveyor.   
     
     
         2 . A linear process tool as in  claim 1  wherein said substrate is a large area substrate. 
     
     
         3 . A linear process tool as in  claim 2  wherein said substrate has an area greater than one square meter. 
     
     
         4 . A linear process tool as in  claim 1  wherein said substrate is a sheet of flexible material and said linear conveyor moves said sheet from a first reel at a first end of said linear process tool to a second reel at a second end of said linear process tool. 
     
     
         5 . A linear process tool as in  claim 1  wherein said micro-plasma process unit includes:
 a first array of micro-plasma spray guns for depositing a catalyst material; and   a second array of micro-plasma spray guns for depositing said carbon nanotubes;   wherein said first array and said second array are configured so that said substrate moves on said linear conveyor under said first array and then under said second array.   
     
     
         6 . A linear process tool as in  claim 1  wherein said substrate is electrically biased with respect to said micro-plasma process unit. 
     
     
         7 . A linear process tool as in  claim 1  further comprising a shower-head plasma deposition unit, said shower-head plasma deposition unit being positioned above said linear conveyor and configured to deposit material on the surface of said substrate as said substrate passes under said shower-head plasma deposition unit on said linear conveyor. 
     
     
         8 . A linear process tool as in  claim 7  wherein said shower-head plasma deposition unit is made of ceramic material. 
     
     
         9 . A method of depositing carbon nanotubes on a substrate comprising:
 supplying a precursor for said carbon nanotubes to an array of micro-plasma spray guns;   creating a plasma using said array of micro-plasma spray guns and said precursor; and   moving said substrate through said plasma.   
     
     
         10 . A method of depositing carbon nanotubes as in  claim 9  wherein said precursor includes a mixture of xylene and ferocene. 
     
     
         11 . A method of depositing carbon nanotubes as in  claim 9  further comprising applying an electrical bias between said substrate and said array of micro-plasma spray guns. 
     
     
         12 . A method of depositing carbon nanotubes as in  claim 9  further comprising, before said creating step, applying a catalyst material to said substrate. 
     
     
         13 . A method of depositing carbon nanotubes as in  claim 12  further comprising activating said catalyst material. 
     
     
         14 . A method of depositing carbon nanotubes as in  claim 13  wherein said activating includes heating said catalyst material. 
     
     
         15 . A method of depositing carbon nanotubes on a substrate comprising:
 supplying a first precursor for a catalyst material to a first array of micro-plasma spray guns;   creating a first plasma using said first array of micro-plasma spray guns and said first precursor;   moving said substrate through said first plasma;   activating said catalyst material;   supplying a second precursor for said carbon nanotubes to a second array of micro-plasma spray guns;   creating a second plasma using said second array of micro-plasma spray guns and said second precursor; and   moving said substrate through said second plasma.   
     
     
         16 . A method of depositing carbon nanotubes on a substrate as in  claim 15  wherein said activating includes heating said catalyst material. 
     
     
         17 . A method of depositing carbon nanotubes on a substrate as in  claim 15  wherein said activating includes exposing said catalyst material to said second plasma. 
     
     
         18 . A method of depositing carbon nanotubes on a substrate as in  claim 15  wherein said first array of micro-plasma spray guns and said second array of micro-plasma spray guns are in the same micro-plasma deposition unit.