Directed assembly of highly-organized carbon nanotube architectures

Abstract

A method of controllably aligning carbon nanotubes to a template structure to fabricate a variety of carbon nanotube containing structures and devices having desired characteristics is provided. The method allows simultaneous, selective growth of both vertically and horizontally controllably aligned nanotubes on the template structure but not on a substrate in a single process step.

1 . A method of making carbon nanotubes, comprising: 
 providing a substrate containing a template structure having at least two surfaces;    providing a nanotube source gas onto the template structure; and    selectively and simultaneously growing the carbon nanotubes on the at least two surfaces of the template structure but not on exposed portions of the substrate such that the grown carbon nanotubes are controllably aligned in a direction perpendicular to a respective surface of the template structure.    
     
     
         2 . The method of  claim 1 , wherein the nanotube source gas comprises xylenes and ferrocene provided onto the template structure in a chemical vapor deposition apparatus.  
     
     
         3 . The method of  claim 2 , wherein: 
 the carbon nanotubes comprise multiwalled carbon nanotubes;    carbon nanotubes are grown at a temperature of 600 to 1100° C.;    the substrate comprises a silicon substrate;    the template structure comprises a silicon dioxide template structure that is not coated with a carbon nanotube growth catalyst; and    the carbon nanotubes simultaneously grow in orthogonal directions on orthogonal template structure surfaces.    
     
     
         4 . The method of  claim 1 , wherein the carbon nanotubes simultaneously grow on plural side surfaces of the template structure in a direction parallel to a surface of the substrate.  
     
     
         5 . The method of  claim 1 , wherein the carbon nanotubes simultaneously grow on an upper surface and on at least one side surface of the template structure.  
     
     
         6 . The method of  claim 1 , wherein the carbon nanotubes simultaneously selectively grow in different directions on plural surfaces of the template structure.  
     
     
         7 . A method of making carbon nanotubes, comprising: 
 providing a substrate containing a template structure, wherein the template structure comprises at least one inclined surface with an oblique inclination which is neither orthogonal nor parallel with respect to an upper plane of the substrate;    providing a nanotube source gas onto the template structure; and    selectively growing the carbon nanotubes on the inclined surface of the template structure but not on exposed portions of the substrate, such that the grown carbon nanotubes comprise a membrane having an open truncated cone shape.    
     
     
         8 . The method of  claim 7 , wherein: 
 the nanotube source gas comprises xylenes and ferrocene provided onto the template structure in a chemical vapor deposition apparatus at a temperature of 600 to 1100° C.;    the carbon nanotubes comprise multiwalled carbon nanotubes;    the substrate comprises a silicon substrate; and    the template structure comprises a silicon dioxide template structure.    
     
     
         9 . The method of  claim 7 , wherein the carbon nanotubes simultaneously grow on an upper surface and on the inclined surface of the template structure.  
     
     
         10 . The method of  claim 7 , further comprising forming a masking layer on an upper surface of the template structure, such that the carbon nanotubes selectively grow on the inclined surface of the template structure but not on the upper surface of the template structure.