Block copolymers with high flory-huggins interaction parameters for block copolymer lithography
Block copolymers for use in block copolymer lithography, self-assembled films of the block copolymers and methods for polymerizing the block copolymers are provided. The block copolymers are characterized by high Flory-Huggins interaction parameters (χ). The block copolymers can be polymerized from protected hydroxystyrene monomers or from tert-butyl styrene and 2-vinylpyridine monomers.
1. A method of transferring a pattern into a substrate using a PtBuSt-b-P2VP block copolymer, the method comprising:
depositing the PtBuSt-b-P2VP block copolymer over the substrate and subjecting the PtBuSt-b-P2VP block copolymer to conditions that induce it to self-assemble into a plurality of domains;
selectively removing some of the domains, such that the self-assembled PtBuSt-b-P2VP block copolymer layer defines a pattern over the substrate; and
transferring the pattern into the substrate to provide a patterned substrate.
2. The method of claim 1 , wherein the plurality of domains includes domains having at least one dimension that is no greater than 100 nm.
3. The method of claim 1 , wherein the plurality of domains includes domains having at least one dimension that is no greater than 20 nm.
4. The method of claim 1 , wherein the plurality of domains includes domains having at least one dimension that is no greater than 10 nm.
5. The method of claim 4 , wherein the plurality of domains comprises cylinders.
6. The method of claim 1 , wherein the plurality of domains comprises cylinders.
7. The method of claim 6 , wherein the cylinders have diameters of no greater than 100 nm.
8. The method of claim 6 , wherein the cylinders are oriented perpendicular with respect to a surface of the substrate.
9. The method of claim 6 , wherein the cylinders are oriented parallel with respect to a surface of the substrate.
10. The method of claim 1 , wherein the plurality of domains comprises lamellae oriented perpendicular with respect to a surface of the substrate.
11. The method of claim 10 , wherein the lamellae have a thickness of no greater than 100 nm.
12. The method of claim 1 , wherein the volume fraction of P2VP in the block copolymer is in the range from 0.19 to 0.69.
13. The method of claim 1 , wherein transferring the pattern into the substrate to provide a patterned substrate comprises selectively chemically modifying exposed regions of the substrate surface.
14. The method of claim 1 , wherein transferring the pattern into the substrate to provide a patterned substrate comprises selectively removing exposed regions of the substrate surface.
15. The method of claim 1 , wherein transferring the pattern into the substrate to provide a patterned substrate comprises selectively coating exposed regions of the substrate surface.
16. The method of claim 1 , wherein selectively removing some of the domains, such that the self-assembled PtBuSt-b-P2VP block copolymer layer defines a pattern over the substrate comprises seeding the P2VP blocks of the block copolymer with a metal and then etching the P2VP.