US Patent 7479052 - Growth of CNT field emitters in amorphous carbon layer

http://www.freepatentsonline.com/7479052.html

Carbon nanotube based field emission arrays have the potential to provide larger area flat panel displays with higher energy efficiency. However, if the density of the nanotubes is too high a field screening effect can result which reduces the efficiency. This patent from Samsung teaches one solution that uses an amorphous carbon layer to regulate the nanotubes grown from a substrate. Claim 1 reads:

1. A method of growing carbon nanotubes, comprising:

preparing a substrate;

forming a catalyst metal layer on the substrate to promote growing of carbon nanotubes;

forming an amorphous carbon layer on the catalyst metal layer, the amorphous carbon layer partially covering the catalyst metal layer; and

growing carbon nanotubes from a surface of the catalyst metal layer, the carbon nanotubes being grown on a portion of the surface of the catalyst metal layer that is not covered by the amorphous carbon layer.