Method for controlled density growth of carbon nanotubes
AssigneeBrother International Corporation
InventorFarzad Parsapour
Life of this patent
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Abstract
Described is a method for preparation of carbon nanotubes (CNTs) with medium to low-site density growth for use in field emission devices (FEDs). The method involves the deposition of a non-catalytic metal layer (interlayer), preferably a metallic conductor, onto the surface of a substrate, prior to the deposition of a catalytic layer (overlayer). The interlayer allows for only partial (sparse) growth of CNTs on the substrate, and helps to prevent resist layer “lift-off” when photolithographic processing is employed.
Claims18
A method for fabricating a carbon nanotube array having a low site-density growth, which method comprises:
- providing a substrate;
- forming a non-catalytic metal interlayer on the substrate, the non-catalytic metal interlayer having a thickness of from about 0.6 nm to about 2.0 nm;
- forming a catalytic metal overlayer on the non-catalytic metal interlayer, the catalytic metal overlayer having a thickness of from about 1.0 nm to about 5.5 nm and defined by a plurality of separate pads disposed on the surface of at least a portion of the non-catalytic metal interlayer;
- and
- forming the plurality of carbon nanotube structures on the substrate in the presence of the catalytic metal overlayer, the carbon nanotube structures having a density of no more than 1010 nanotubes/cm2.
A carbon nanotube array, comprising:
- a substrate;
- a non-catalytic metal interlayer disposed over at least a portion of the substrate;
- and
- a plurality of catalytic metal overlayer pads disposed on the surface of at least a portion of the non-catalytic interlayer, a plurality of carbon nanotubes disposed on each pad with a density of no more than 1010 nanotubes/cm2;
- wherein
- the non-catalytic metal interlayer has a thickness of from about 0.6 nm to about 2.0 nm, and wherein the catalytic metal overlayer pads have a thickness of from about 1.0 nm to about 5.5 nm.
A field emission display, comprising:
- a cathode;
- an anode;
- a carbon nanotube array disposed on the cathode, the carbon nanotube array comprising
- a non-catalytic metal interlayer disposed over at least a portion of the cathode;
- and
- a plurality of catalytic metal overlayer pads disposed on the surface of at least a portion of the non-catalytic interlayer, a plurality of carbon nanotubes disposed on each pad with a density of no more than 1010 nanotubes/cm2;
- wherein
- the non-catalytic interlayer has a thickness of from about 0.6 nm to about 2.0 nm, and wherein the catalytic metal overlayer pads have a thickness of from about 1.0 nm to about 5.5 nm.
Dependencies are inferred from the claim text.