Removing Undesirable Nanotubes During Nanotube Device Fabrication

Abstract

Fabricating single-walled carbon nanotube transistor devices includes removing undesirable types of nanotubes. These undesirable types of nanotubes may include nonsemiconducting nanotubes, multiwalled nanotubes, and others. The undesirable nanotubes may be removed electrically using voltage or current, or a combination of these. This approach to removing undesirable nanotubes is sometimes referred to as “burn-off.” The undesirable nanotubes may be removed chemically or using radiation. The undesirable nanotubes of an integrated circuit may be removed in sections or one transistor (or a group of transistors) at a time in order to reduce the electrical current used or prevent damage to the integrated circuit during burn-off.

1 . A method comprising:
 providing a template having a top surface and a bottom surface comprising a plurality of openings extending into the template from the top surface toward the bottom surface;   processing to obtain a mixture of a first type of nanotubes and a second type of nanotubes in the openings of the template;   providing a first electrode to couple to first ends of the mixture of nanotubes;   providing a second electrode to couple to second ends of the mixture of nanotubes;   forming a gate electrode on the template; and   applying voltages to the gate and the first and second electrode to cause a current to flow through the second type of nanotubes, wherein greater numbers of the second type of nanotubes are destroyed by the current than the first type of carbon nanotubes.   
     
     
         2 . The method of  claim 1  wherein the first type of nanotubes comprise single-walled carbon nanotubes and the second type of nanotubes comprise metallic carbon nanotubes.