Nanoimprint lithography formation of functional nanoparticles using dual release layers
View Patent ↗Functional nanoparticles may be formed using at least one nanoimprint lithography step. In one embodiment, sacrificial material may be patterned on a multilayer substrate including one or more functional layers between removable layers using an imprint lithography process. At least one of the functional layers includes a functional material such as a pharmaceutical composition or imaging agent. The pattern may be further etched into the multilayer substrate. At least a portion of the functional material may then be removed to provide a crown surface exposing pillars. Removing the removable layers releases the pillars from the patterned structure to form functional nanoparticles such as drug or imaging agent carriers.
1. An imprint lithography method for forming nanoparticles comprising:
forming a multilayer substrate comprising a base layer, a first removable layer bonded to the base layer, one or more functional layers bonded to the first removable layer; and a second removable layer bonded to one of the functional layers, wherein at least one of the one or more functional layers contains a functional material;
forming a patterned layer on a surface of the multilayer substrate in an imprint lithography process, the patterned layer comprising a multiplicity of projections and recessions;
transferring the features of the patterned layer into the multilayer substrate in one or more etching processes to form a plurality of multilayer pillars extending from the base layer;
dissolving the first and second removable layers with a solvent to separate pillars containing the one or more functional layers from the base layer, the separated pillars defining nanoparticles.
2. The method of claim 1 wherein the functional material is a pharmaceutical composition.
3. The method of claim 1 wherein the functional material is an imaging agent.
4. The method of claim 1 further comprising forming a hard mask layer on the patterned layer, and then etching away at least a portion of the hard mask layer before transferring the features of the patterned layer into the multilayer substrate in one or more etching processes to form a plurality of multilayer pillars extending from the base layer.
5. The method of claim 1 further comprising forming a hard mask layer over the second removable layer.
6. The method of claim 1 wherein the transferring further substantially removes the patterning layer.
7. The method of claim 1 wherein at least one of the etching processes comprises an inert gas etching process.
8. The method of claim 1 further comprising dissolving the second removable layer with a first solvent, wherein the first solvent selectively dissolves the second removable layer; and
dissolving the first removable layer with a second solvent, wherein the second solvent selectively dissolves the first removable layer to separate the pillars from the base layer.
9. The method of claim 1 further comprising treating the surfaces of the multilayer pillars before dissolving the first removable layer.
10. The method of claim 9 wherein the surface treating further comprises coating the surface of the multilayer substrate.
11. The method of claim 9 wherein the surface treating further comprises modifying the surface of the multilayer substrate.
12. The method of claim 11 wherein the modifying is selected from the group consisting of coupling ligands or other functional molecules to the surface, modifying surface charge, and modifying the hydrophobicity or the hydrophilicity of the surface.
13. An imprint lithography method comprising:
forming a multilayer substrate comprising a base layer, a first removable layer coupled to the base layer, one or more functional layers coupled to the first removable layer, and a second removable layer coupled to one of the functional layers, wherein at least one of the functional layers comprises contains a functional material;
forming a hard mask layer on the multilayer substrate;
forming a patterned layer over the hard mask layer in an imprint lithography process, the patterned layer comprising a multiplicity of projections and recessions;
transferring the features of the patterned layer into the hard mask and multilayer substrate in one or more etching processes to form a plurality of multilayer pillars extending from the base layer; and
dissolving the first removable layer and the second removable layer with a solvent to separate the multilayer pillars from the base layer.
14. The method of claim 13 wherein the functional material is a pharmaceutical composition.
15. The method of claim 13 wherein the functional material is an imaging agent.
16. The method of claim 13 wherein the transferring further substantially removes the patterning layer and the hard mask.
17. The method of claim 13 further comprising dissolving the second removable layer with a first solvent, wherein the first solvent selectively dissolves the second removable layer; and
dissolving the first removable layer with a second solvent, wherein the second solvent selectively dissolves the first removable layer to separate the pillars from the base layer.