Catalyst patterning for nanowire devices
AssigneeIntegrated Nanosystems, Inc.
InventorsJun Li, Alan M. Cassell, Jie Han
Life of this patent
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Abstract
Nanowire devices may be provided that are based on carbon nanotubes or single-crystal semiconductor nanowires. The nanowire devices may be formed on a substrate. Catalyst sites may be formed on the substrate. The catalyst sites may be formed using lithography, thin metal layers that form individual catalyst sites when heated, collapsible porous catalyst-filled microscopic spheres, microscopic spheres that serve as masks for catalyst deposition, electrochemical deposition techniques, and catalyst inks. Nanowires may be grown from the catalyst sites.
Claims18
A method for forming a plurality of catalyst sites from which to grow nanowires for a nanowire device that has a substrate with an upper surface, the method comprising:
- depositing a layer of catalyst on the upper surface of the substrate;
- and
- heating the substrate and catalyst sufficiently to cause the catalyst to migrate along the surface of the substrate to form individual clumps of catalyst, wherein the clumps serve as the catalyst sites for nanowire growth.
A method for forming a plurality of catalyst sites from which to grow nanowires for a nanowire device that has a substrate with an upper surface, the method comprising:
- applying a layer of resist to the substrate;
- using deep UV lithography to pattern the resist to form a plurality of holes in the resist at desired locations on the upper surface of the substrate;
- depositing a layer of catalyst on the patterned resist;
- and
- removing the resist after the catalyst has been deposited to leave catalyst at the catalyst sites.
A method for forming a plurality of catalyst sites in a desired pattern from which to grow nanowires for a nanowire device that ha s a substrate with an upper surface, the method comprising:
- impregnating a template having a pattern of raised features that match the desired pattern of the catalyst sites with a catalyst solution;
- and
- placing the template against the upper surface to release catalyst solution onto the upper substrate surface in the desired pattern, wherein the catalyst solution forms catalyst at the catalyst sites when dry.
A method for forming a plurality of catalyst sites from which to grow nanowires for a nanowire device that has a substrate with an upper surface, the method comprising:
- applying a layer of material to the substrate that has a plurality of holes, wherein the holes define desired locations for the catalyst sites;
- immersing the substrate in a liquid containing catalyst;
- and
- forming the catalyst sites for nanowire growth by depositing catalyst metal in the holes from the liquid.
A method for forming a plurality of catalyst sites from which to grow nanowires for a nanowire device that has a substrate with an upper surface, the method comprising:
- applying a layer of microscopic spheres to the upper surface;
- depositing a layer of catalyst on top of the microscopic spheres, so that catalyst is deposited on the upper surface in interstitial regions defined by the microscopic spheres;
- and
- removing the microscopic spheres from the upper surface after the catalyst has been deposited so that catalyst remains on the upper surface at the catalyst sites.
A method for forming a plurality of catalyst sites from which to grow nanowires for a nanowire device that has a substrate with an upper surface, the method comprising:
- applying a layer of microscopic porous spheres filled with catalyst to the upper surface;
- applying heat to the microscopic porous spheres to transform the microscopic porous spheres into the catalyst sites.
Dependencies are inferred from the claim text.