Release agent partition control in imprint lithography
View Patent ↗Release agents with increased affinity toward nano-imprint lithography template surfaces interact strongly with the template during separation of the template from the solidified resist in a nano-imprint lithography process. The strong interaction between the surfactant and the template surface reduces the amount of surfactant pulled off the template surface during separation of a patterned layer from the template in an imprint lithography cycle. Maintaining more surfactant associated with the surface of the template after the separation of the patterned layer from the template may reduce the amount of surfactant needed in a liquid resist to achieve suitable release of the solidified resist from the template during an imprint lithography process. Strong association of the release agent with the surface of the template facilitates the formation of ultra-thin residual layers and dense fine features in nano-imprint lithography.
1. An imprint lithography release agent comprising:
a non-polar fluorinated portion comprising a perfluorinated polyether; and
a polar poly(oxyalkylene) portion bonded to the non-polar fluorinated portion, the polar poly(oxyalkylene) portion formed from a multiplicity of oxyalkylene units comprising at least one ethylene oxide unit.
2. The imprint lithography release agent of claim 1 , wherein the multiplicity of oxyalkylene units comprises at least three ethylene oxide units.
3. The imprint lithography release agent of claim 1 , wherein the multiplicity of oxyalkylene units comprises at least one propylene oxide unit.
4. The imprint lithography release agent of claim 3 , wherein the multiplicity of oxyalkylene units comprises at least three propylene oxide units.
5. The imprint lithography release agent of claim 1 , the release agent having the chemical structure
wherein each R a is independently H 3 C[OCH 2 CH 2 ] x [OCH 2 CHCH 3 ] y , and m, n, x, and y are integers.
6. An imprint lithography release agent comprising:
a non-polar fluorinated portion comprising a perfluorinated polyether; and
a polar portion bonded to the non-polar fluorinated portion, wherein the polar portion forms polar interactions with a surface comprising oxygen.
7. The imprint lithography release agent of claim 6 , wherein the polar portion comprises a carboxyl group.
8. The imprint lithography release agent of claim 6 , wherein the polar portion comprises two or more hydroxyl groups.
9. The imprint lithography release agent of claim 6 , wherein the polar portion comprises a nitrogen atom.
10. The imprint lithography release agent of claim 9 , wherein nitrogen atom is part of a heterocycle.
11. The imprint lithography release agent of claim 9 , wherein the polar portion comprises two nitrogen atoms.
12. The imprint lithography release agent of claim 11 , wherein the polar portion comprises a pyridazinyl group.
13. The imprint lithography release agent of claim 6 , wherein the polar interactions are hydrogen bonding interactions.
14. The imprint lithography release agent of claim 6 , wherein the polar interactions form a cyclic structure at the surface.
15. The imprint lithography release agent of claim 6 , wherein the release agent forms a covalent bond with the surface, and the strength of the covalent bond is less than the strength of a silicon-oxygen bond at the surface.
16. The imprint lithography release agent of claim 15 , wherein the release agent comprises a boron atom, and the covalent bond is formed between the boron atom and the surface.
17. The imprint lithography release agent of claim 6 , the release agent having the chemical structure
or a derivative thereof, wherein R f ′ is
CH 2 CF 2 O(CF 2 CF 2 O) m (CF 2 O) n CF 2 CH 2
and m, n, x, and y are integers.
18. The imprint lithography release agent of claim 6 , having the chemical structure
wherein m and n are integers and R 1 and R 2 are carbon-containing.
19. A imprint lithography liquid resist comprising:
a monomer;
a cross-linking agent;
a photoinitiator;
a catalyst; and
a release agent comprising:
a non-polar fluorinated portion comprising a perfluorinated polyether; and
a polar poly(oxyalkylene) portion bonded to the non-polar fluorinated portion, the polar poly(oxyalkylene) portion formed from a multiplicity of oxyalkylene units comprising at least one ethylene oxide unit.
20. The liquid resist of claim 19 , wherein the multiplicity of oxyalkylene units comprises at least one propylene oxide unit.
21. The liquid resist of claim 19 , further comprising a compound comprising a perfluorinated polyether group and one or more acrylate groups.
22. The liquid resist of claim 21 , wherein the compound comprising the perfluorinated polyether group and the one or more acrylate groups has the chemical structure
wherein m and n are integers.
23. The liquid resist of claim 21 , wherein the compound comprising the perfluorinated polyether group and the one or more acrylate groups has the chemical structure
wherein m, n, x, and y are integers.