Method of producing nanopatterned articles, and articles produced thereby
View Patent ↗A nanopatterned surface is prepared by forming a block copolymer film on a miscut crystalline substrate, annealing the block copolymer film, then reconstructing the surface of the annealed block copolymer film. The method creates a well-ordered array of voids in the block copolymer film that is maintained over a large area. The nanopatterned block copolymer films can be used in a variety of different applications, including the fabrication of high density data storage media.
1. A layered article, comprising:
a crystalline substrate comprising an annealed, miscut surface; and
a block copolymer film disposed on the annealed, miscut surface; wherein the block copolymer film comprises a block copolymer comprising a first block and a second block;
wherein the block copolymer film comprises
a major block layer contacting the annealed, miscut surface, and comprising at least 65 weight percent of the first block, and
a minor block layer contacting the major block layer, and comprising at least 80 weight percent of the second block; and
wherein the block copolymer film defines a hexagonal array of cylindrical voids extending through the major block layer and the minor block layer.
2. The layered article of claim 1 , further comprising an etch resist layer disposed on the minor block layer of the block copolymer film.
3. The layered article of claim 1 , wherein the first block has a first Hildebrand solubility parameter and the second block has a second Hildebrand solubility parameter, and wherein the first Hildebrand solubility parameter and the second Hildebrand solubility parameter differ by at least 0.4 megapascal 1/2 .
4. The layered article of claim 3 , wherein the first block and the second block differ in number average molecular weight by at least a factor of 1.5.
5. The layered article of claim 1 , wherein the block copolymer is a polystyrene-poly(4-vinylpyridine) or polystyrene-poly(2-vinylpyridine) diblock copolymer.
6. The layered article of claim 1 , wherein the block copolymer is a polystyrene-poly(ethylene oxide) diblock copolymer.
7. The layered article of claim 1 , wherein the block copolymer film has a thickness of about 10 to about 100 nanometers.
8. The layered article of claim 1 , wherein the crystalline substrate consists essentially of a single crystal.
9. The layered article of claim 1 , wherein the crystalline substrate is selected from the group consisting of crystalline silicon, doped crystalline silicon, and crystalline aluminum oxide.
10. The layered article of claim 1 , wherein the crystalline substrate comprises crystalline silicon.
11. The layered article of claim 1 , wherein the crystalline substrate comprises crystalline aluminum oxide.
12. The layered article of claim 1 , wherein the miscut crystalline surface is at least one degree removed from any crystallographic plane of the crystalline substrate.
13. The layered article of claim 1 , wherein the annealed, miscut surface of the crystalline substrate exhibits a saw-tooth pattern characterized by a peak-to-peak separation of about 24 to about 200 nanometers and a peak-to-valley separation of about 3 to about 20 nanometers.
14. The layered article of claim 1 , wherein the annealed, miscut surface of the crystalline substrate exhibits a grooved pattern characterized by a groove depth of about 3 to about 20 nanometers and a groove-to-groove separation of about 24 to about 200 nanometers.
15. The layered article of claim 1 , wherein the annealed, miscut surface of the crystalline substrate is chemically homogeneous.