US Patent 7431964 - Angular porous metal film deposition for nanotube growth

http://www.freepatentsonline.com/7431964.html

This patent to Motorola teaches forming a porous metal catalyst film to support the growth of carbon nanotubes for field emission. Angular deposition is used to control the nanotube spacing. Claim 1 reads:

1. A method comprising:

providing a substrate having a surface;

depositing a metal onto the substrate at an angle to the surface resulting in a porous metal layer;

depositing a metal catalyst as a plurality of particles onto the porous metal layer; and

forming nanotubes on the metal catalyst particles.