Control of self-assembly of lithographically patternable block copolymer films.
Poly(alpha-methylstyrene)-block-poly(4-hydroxystyrene) acts as both a lithographic deep UV photoresist and a self-assembling material, making it ideal for patterning simultaneously by both top-down and bottom-up fabrication methods. Solvent vapor annealing improves the quality of the self-assembled patterns in this material without compromising its ability to function as a photoresist. The choice of solvent used for annealing allows for control of the self-assembled pattern morphology. Annealing in a nonselective solvent (tetrahydrofuran) results in parallel orientation of cylindrical domains, while a selective solvent (acetone) leads to formation of a trapped spherical morphology. Finally, we have self-assembled both cylindrical and spherical phases within lithographically patterned features, demonstrating the ability to precisely control ordering. Observing the time evolution of switching from cylindrical to spherical morphology within these features provides clues to the mechanism of ordering by selective solvent.
Bosworth
Joan K
JK
Department of Materials Science and Engineering, Bard Hall, Cornell University, Ithaca, New York 14853, USA.
Paik
Marvin Y
MY
Ruiz
Ricardo
R
Schwartz
Evan L
EL
Huang
Jenny Q
JQ
Ko
Albert W
AW
Smilgies
Detlef-M
DM
Black
Charles T
CT
Ober
Christopher K
CK
D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008567:Membranes, Artificial; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry*; D013499:Surface Properties
D046911:Macromolecular Substances; D008567:Membranes, Artificial; D011137:Polystyrenes