| 초록 |
To apply Block copolymer to nanolithographic application, vertically oriented nanodomains in thin film are needed. To achieve vertical oriented nanodomains, various methods were introduced. Previously, our group showed that when the chain architecture of BCPs is star shape, vertically oriented nanodomains were obtained by using only thermal annealing without any special pre-/post- treatment. Here, we study the effect of the molecular weight of star BCP on the orientation of nanodomains in thin films on various substrates. For this purpose, we synthesized (PMMA-b-PS)6 with two different PMMA volume fractions (fPMMA=0.32 and 0.52). As the molecular weight of (PMMA-b-PS)6 increased, the orientation of nanostructures on a silicon oxide changed from parallel to vertical. When the molecular weight is small, but a little larger than the critical molecular weight corresponding to the order-disorder transition (ODT), the orientation of nanostructures is greatly affected by a substrate. |
