| 초록 |
Block copolymer self-assembly can generate various nanostructures with small features in the size range of 5-50 nm such as dot, line, hole, and ring patterns, making it one of the promising candidates for next-generation lithography. However, there are critical issues to achieve rapid self-assembly of BCPs with a high Flory-Huggins interaction parameter (χ), resulting from the exponential decrease of BCP chain mobility in proportion to the χ-value. In this study, in order to solve the issues, we employed binary solvent-vapor-annealing system to induce fast swelling of poly(styrene-b-dimethylsiloxane) (PS-b-PDMS) BCPs with high-χ (~ 0.26). We systemically investigated how mixed solvent of PS-swelling solvent (toluene), PDMS-swelling solvent (heptane) and more selective solvent for PDMS (pentane) affect BCP self-assembly kinetics. We found the optimum mixing ratio for several BCPs with different molecular weights (MWs) and volume fraction (fPDMS), showing ultra-fast pattern formation time (＜ 5 min) to realize highly ordered BCP patterns. We also explored how less selective solvent (dimethylformamide, DMF) for PS-b-PDMS BCPs affect self-assembly speed for getting well-ordered structures. Furthermore, extremely fast pattern-generation of 12-nm-dot-structure was successfully accomplished within 10 seconds in the narrow trench (width: ~200 nm) through the binary-solvent-annealing process. We believe that these results which are extendable for the other high-χ BCPs and mixed solvents combinations apparently can contribute to ultra-fine lithography applications. |
