Fabrication of complex three-dimensional structures based on directed assembly of self-assembling materials on activated two-dimensional templates
Methods of fabricating complex three-dimensional structures on patterned substrates and related compositions are provided. The methods involve depositing on the substrate a block copolymer material that is “mismatched” to the substrate pattern, and then ordering the material to form a complex three-dimensional structure. According to various embodiments, the copolymer material mismatches the substrate pattern in that the symmetry and/or length scale of its bulk morphology differs from that of the pattern. When ordered, a balance between the physics that determines the bulk block copolymer morphology and the physics that determines the substrate surface interfacial interactions results in a thermodynamically stable complex three-dimensional film that varies in a direction perpendicular to the substrate and has a morphology that differs from its bulk morphology.
1. A structure comprising:
a chemically patterned substrate, the chemical pattern comprising discrete regions of a first chemical functionality surrounded by a second chemical functionality; and
a phase separated block copolymer thin film overlying the chemically patterned substrate, the film including discrete elements of a first phase in a matrix of a second phase, wherein a first set of the discrete elements of the first phase overlie the discrete regions of the first chemical functionality and a second set of the discrete elements of the first phase overlie the second chemical functionality.
2. The structure of claim 1 , wherein the first set of the discrete elements overlie the discrete regions of the first chemical functionality in a 1:1 correspondence.
3. The structure of claim 1 , wherein the first set of the discrete elements is arranged in an ordered array.
4. The structure of claim 1 , wherein the second set of the discrete elements is arranged in an ordered array.
5. The structure of claim 1 , wherein the first set of the discrete elements is arranged in a first array and the second set of the discrete elements is arranged in a second array such that the first and second arrays are interposed.
6. The structure of claim 1 , wherein one or more of the phases of the phase separated block copolymer thin film is selected from the group consisting of polystryrene, poly(methyl methacrylate), poly(isoprene), poly(ethylene oxide), and poly(acrylic acid).
7. The structure of claim 1 , wherein the block copolymer has a cylinder bulk morphology.
8. The structure of claim 1 , wherein the block copolymer has a spherical bulk morphology.
9. The structure of claim 1 , wherein a length scale of the discrete regions of the chemical pattern is greater than the corresponding length scale of the bulk morphology of the block copolymer.
10. A method comprising:
providing a chemically patterned substrate, the chemical pattern comprising discrete regions of a first chemical functionality surrounded by a second chemical functionality;
depositing a layer of material comprising a block copolymer on the substrate; and
inducing the material to undergo phase separation thereby forming a phase separated block copolymer thin film on the chemical pattern, wherein the film comprises discrete elements of a first phase in a matrix of a second phase, wherein a first set of the discrete elements of the first phase overlie the regions of the first chemical functionality, and wherein a second set of the discrete elements of the first phase overlie the second chemical functionality.
11. The method of claim 10 , wherein the chemical pattern has a first length scale and wherein the bulk morphology of the block copolymer has a corresponding second length scale that differs from the first length scale.
12. The method of claim 11 , wherein the first length scale is greater than the second length scale.
13. The method of claim 10 , wherein the first set of the discrete elements overlie the discrete regions of the first chemical functionality in a 1:1 correspondence.
14. The method of claim 10 , wherein the first set of the discrete elements is arranged in a first array and the second set of the discrete elements is arranged in a second array such that the first and second arrays are interposed.
15. The method of claim 10 , wherein the material comprises one or more of:
polystryrene, poly(methyl methacrylate), poly(isoprene), poly(ethylene oxide), and poly(acrylic acid).
16. The method of claim 10 , wherein the block copolymer has a cylinder bulk morphology.
17. The method of claim 10 , wherein the block copolymer has a spherical bulk morphology.
18. The method of claim 10 , wherein the first set of the discrete elements is arranged in a first array and the second set of the discrete elements is arranged in a second array such that the first and second arrays are interposed.