Compositions and processes for self-assembly of block copolymers

1. A composition comprising at least one random copolymer having at least one unit of structure (1), at least one unit of structure (2), at least one unit of structure (3), one H end group, and one end group having structure (1′);

where R 1 is selected from the group consisting of a C 1 -C 8 alkyl, C 1 -C 8 fluoroalkyl, C 1 -C 8 partially fluorinated alkyl moiety, C 4 -C 8 cycloalkyl, C 4 -C 8 cyclofluoroalkyl, C 4 -C 8 partially fluorinated cycloalkyl, and a C 2 -C 8 hydroxyalkyl;

R 2 , R 3 and R 5 are independently selected from a group consisting of H, C 1 -C 4 alkyl, CF 3 and F; R 4 is selected from the group consisting of H, C 1 -C 8 alkyl, C 1 -C 8 partially fluorinated alkyl moiety and C 1 -C 8 fluoroalkyl; n ranges from 1 to 5;

R 6 is selected from the group consisting of H, F, C 1 -C 8 alkyl and a C 1 -C 8 fluoroalkyl; m ranges from 1 to 3; n′ ranges from 1 to 5; n″ ranges from 1 to 5; n′″ ranges from 1 to 5; R 7 is a C 1 -C 8 alkyl; X is —CN or an alkyloxycarbonyl moiety R 8 —O—(C═O)— where R 8 is a C 1 -C 8 alkyl; and represents the attachment point of the end group to the random copolymer, where the composition further comprises a solvent.

2. The composition of claim 1 , where the copolymer is capable of forming a layer which is grafted, cross-linked, and a neutral layer relative to a block copolymer.

3. The composition of claim 1 , where the copolymer is capable of forming a layer which is a grafted, cross-linked, and a neutral layer which is not soluble in an organic solvent for photoresist.

4. The composition of claim 1 , where the copolymer is capable of forming a layer which is a grafted, cross-linked, and a neutral layer which is not soluble in an aqueous alkaline developer.

5. The composition of claim 1 , where R 1 is selected from the group consisting of a C 1 -C 8 alkyl; R 2 , R 3 and R 5 are independently selected from the group consisting of H and C 1 -C 4 alkyl; R 4 is selected from the group consisting of H, C 1 -C 8 alkyl, and n=1; and R 6 is selected from the group consisting of H, C 1 -C 8 alkyl, and m=1.

6. The composition of claim 1 , where the unit of structure (3) ranges from 10 mole % to 45 mole %.

7. The composition of claim 2 , where the block copolymer is poly(styrene-b-methylmethacrylate).

8. The composition of claim 1 , which further comprises an acid generator.

9. The composition of claim 1 , which further comprises a thermal acid generator.

10. A random copolymer having at least one repeat unit of structure (1), at least one repeat unit of structure (2), at least one repeat unit of structure (3) one H end group, and one end group having structure (1′);

where R 1 is selected from the group consisting of a C 1 -C 8 alkyl, C 1 -C 8 fluoroalkyl, C 1 -C 8 partially fluorinated alkyl moiety, C 4 -C 8 cycloalkyl, C 4 -C 8 cyclofluoroalkyl, C 4 -C 8 partially fluorinated cycloalkyl, and a C 2 -C 8 hydroxyalkyl;

R 2 , R 3 and R 5 are independently selected from a group consisting of H, C 1 -C 4 alkyl, CF 3 and F; R 4 is selected from the group consisting of H, C 1 -C 8 alkyl, C 1 -C 8 partially fluorinated alkyl moiety and C 1 -C 8 fluoroalkyl, n ranges from 1 to 5, R 6 is selected from the group consisting of H, F, C 1 -C 8 alkyl and a C 1 -C 8 fluoroalkyl and m ranges from 1 to 3, and n′ ranges from 1 to 5, and n″ ranges from 1 to 5, n′″ ranges from 1 to 5, R 7 is a C 1 to C 8 alkyl and X is —CN, or an alkyloxycarbonyl moiety R 8 —O—(C═O)— where R 8 is a C 1 to C 8 alkyl and represents the attachment point of the end group to the random copolymer where the composition the composition further comprises a solvent.

11. A process for forming a grafted and cross-linked coating of a copolymer on a substrate comprised of the steps:

a) forming a coating of a composition of claim 1 on a substrate;

b) heating the coating at a temperature between 90° C.-180° C. to remove solvent and to form a grafted coating layer of the copolymer;

c) heating the grafted coating layer at a temperature between 200° C.-250° C. to form a cross-linked copolymer coating layer.

12. A process for forming a self-assembled block copolymer coating layer on a neutral layer coating comprised of the steps:

a) forming a coating of a composition of claim 1 on a substrate;

b) heating the coating at a temperature between 90° C.-180° C. to remove solvent and to form a grafted coating layer of the copolymer;

c) heating the grafted coating layer at a temperature between 200° C.-250° C. to cross-link the copolymer forming the neutral coating layer;

d) applying a block copolymer over the neutral coating layer and annealing until directed self-assembly of the block copolymer layer occurs.

13. A process of graphoepitaxy, directed self-assembly of a block copolymer layer used to form an image comprised of the steps:

a) forming a coating of a composition of claim 1 on a substrate;

b) heating the coating at a temperature between 90° C.-180° C. to form a grafted coating layer;

c) heating the grafted coating layer at a temperature between 200° C.-300° C. to form a cross-linked, grafted neutral layer;

d) providing a coating of a photoresist layer over the cross-linked, grafted neutral layer;

e) forming a pattern in the photoresist layer via exposure and development;

f) applying a block copolymer comprising an etch resistant block and a highly etchable block over the photoresist pattern and annealing until directed self-assembly occurs; and,

g) etching the block copolymer, thereby removing the highly etchable block of the copolymer and forming a pattern.

14. The process of claim 13 where the pattern in the photoresist layer is formed by imaging lithography selected from a group consisting of e-beam, broadband, 193 nm immersion lithography, 13.5 nm, 193 nm, 248 nm, 365 nm and 436 nm.

15. A process of chemoepitaxy, directed self-assembly of a block copolymer layer used to form an image comprised of the steps:

a) forming a coating of a composition of claim 1 on a substrate;

b) heating the coating at a temperature between 90° C.-180° C. to remove solvent and form a grafted coating layer;

c) heating the grafted coating layer at a temperature between 200° C.-300° C. to form a cross-linked, grafted neutral layer;

d) providing a coating of a photoresist layer over the cross-linked, grafted neutral layer;

e) forming a pattern in the photoresist layer, via exposure and development thereby forming regions in which the neutral layer is uncovered by the resist;

f) treating the uncovered neutral layer,

g) removing the photoresist,

h) applying a block copolymer comprising an etch resistant block and a highly etchable block over the neutral layer and annealing until directed self-assembly occurs; and,

i) etching the block copolymer, thereby removing the highly etchable block of the copolymer and forming a pattern.

16. The process of claim 14 where the pattern in the photoresist layer is formed by imaging lithography selected from a group consisting of e-beam, broadband, 193 nm immersion lithography, broadband, 13.5 nm, 193 nm, 248 nm, 365 nm and 436 nm.