Hydrophobic pinning mat for directed self-assembly of diblock copolymer novel compositions and processes for self-assembly of block copolymers
The present invention relates to a novel styrenic polymer comprised of the repeat units of structures (I), (II), and (III), wherein R 1 , R 2 and R 3 are individually selected from H or a C-1 to C-4 linear alkyl, R 5 , R 7 and R 6 are individually selected from a C-1 to C-8 linear alkyl, a C-3 to C-8 linear alkyl and a C-3 to C-8 cyclic alkyl and to the novel composition comprised of this polymer and a spin on organic solvent. In another aspect of this invention it pertains to the use of this composition to create a grafted on a substrate, and a further aspect, this grafted film may be used in a directed self-assembly process.
1. A polymer comprised of the repeat units of structures (I), (II), and (III), wherein R1, R2 and R3 are individually selected from H or a C-1 to C-4 linear alkyl, R 5 , R 7 and R 6 are individually selected from a C-1 to C-8 linear alkyl, a C-3 to C-8 linear alkyl and a C-3 to C-8 cyclic alkyl;
2. The polymer of claim 1 , wherein each polymer chain of said polymer contains one hydrogen end group and one end group having structure (IV),
wherein R 8 and R 9 are individually selected from a C-1 to C-8 linear alkyl, a C-3 to C-8 branched alkyl and a C-3 to C-8 cyclic alkyl,
wherein * designates the attachment point of said end group of structure (IV) to said polymer chain,
wherein X is CN or a carbonyloxyalkyl of structure (—C(═O)—O—R 10 ), and
wherein R 10 is selected from a C-1 to C-8 linear alkyl, a C-3 to C-8 branched alkyl and a C-3 to C-8 cyclic alkyl
3. The polymer of claim 1 , wherein R 1 , R 2 and R 3 are H.
4. The polymer of claim 1 , wherein any two of R 5 , R 6 and R 7 are linked together forming a single C-6 to C-24 alkylcycloalkan-1-yl moiety, or wherein all three of R 5 , R 6 and R 7 are linked together to form a C-6 to C-24 tertiary alicyclic moiety.
5. The polymer of claim 1 , wherein R 5 , R 6 and R 7 are each independently selected from a from a C-1 to C-8 linear alkyl, a C-3 to C-8 linear alkyl and a C-3 to C-8 cyclic alkyl.
6. The polymer of claim 1 , wherein R 5 , R 6 and R 7 are each independently selected from a C-1 to C-8 linear alkyl.
7. The polymer of claim 2 , wherein said end group of structure (IV) is one wherein X is CN.
8. The polymer of claim 2 , wherein said end group of structure (IV) is one wherein X is CN and R 8 and R 9 are each independently selected from a C-1 to C-8 linear alkyl.
9. The polymer of claim 2 , wherein said end group of structure (IV) is one wherein X is CN and R 8 and R 9 are methyl.
10. The polymer of claim 1 , wherein the mole % value of repeat unit of structures (I) ranges from about 1 mole % to about 15 mole % of said polymer,
wherein the mole % value of repeat unit of structure (II) ranges from about 5 mole % to about 30 mole % of said polymer, wherein repeat unit of structure (III) ranges from about 75 mole % to about 90 mole % of said polymer and
wherein the sum of the mole % values of the repeat units of structure (I), (II) and (III) add up to 100 mole % of the total moles of repeat units of said polymer.
11. The polymer of claim 1 , wherein the mole % value of repeat unit of structures (I) ranges from about 5 mole % to about 10 mole %,
wherein the mole % value of repeat unit of structure (II) ranges from about 7 mole % to about 15 mole % of said polymer,
wherein repeat unit of structure (III) ranges from about 80 mole % to about 87 mole % of said polymer and
wherein the sum of the mole % values of the repeat units of structure (I), (II) and (III) add up to 100 mole % of the total moles of repeat units of said polymer.
12. A composition comprising said polymer of claim 1 and a spin casting solvent.
13. The composition of claim 12 , wherein the wt % of said polymer is from about 0.2 wt % to about 0.3 wt %.
14. A process of forming a pining layer mat on a substrate comprising the steps;
coating said composition of claim 12 on a substrate forming a film, and
baking said film at a temperature from about 200° C. to about 270° C. for about 1 to about 10 minutes forming a pining layer MAT.
15. The process according to claim 14 wherein said substrate is a silicon BARC.
16. A chemoepitaxy process comprising the steps;
ia) coating said composition of claim 12 on a substrate forming a film,
iia) baking said film at a temperature from about 200° C. to about 315° C. for about 1 to about 10 minutes forming a crosslinked pinning layer MAT,
iiia) patterning said crosslinked pinning layer MAT to form a patterned crosslinked pinning layer MAT,
iva) coating on said patterned crosslinked pinning layer MAT a neutral layer coating,
va) curing said neutral layer coating and washing away with a solvent uncured neutral layer forming in areas of said substrate not covered by said patterned crosslinked pinning layer MAT, a neutral directing layer forming on said substrate forming a chemoepitaxy directing layer,
via) coating on said chemoepitaxy directing layer a block copolymer solution forming a coating of block copolymer,
viia) annealing said coating of block copolymer to form a directed self-assembled film of the block copolymer on said chemoepitaxy directing layer.
17. The chemoepitaxy process of claim 16 , further comprising step viiia):
viiia) using said self-assembled film of the block copolymer as a mask to pattern into the substrate with a plasma etch.
18. The chemoepitaxy process of claim 16 , wherein said substrate is a silicon BARC.
19. The chemoepitaxy process of claim 16 , wherein said block copolymer is a block copolymer of styrene and methyl methacrylate.