Pattern transfer and molecular chain orientation modulation by soft template during the nanoimprint lithography

Abstract

The templates for the nanoimprinting are fabricated usually through a series of steps, such as E-beam lithography, E-beam deposition, liftoff and reactive ion etching. Any mistake during these steps would lead to the failure of the fabrication, so the template is always expensive and difficult to make. Under this circumstance, it is really important to find an effective way to build the template. In this report, the patterned photoresist layer is used as a mother set of the pattern definition of the soft template polydimethylsiloxane. The grating structure of conjugated polymer poly (9,9-dioctylfluorene) film is successfully obtained by this template in the nanoimprinting process. In addition, we also find the anisotropy of molecular chain distribution. Both the transmission electron microscope diffraction pattern and the polarized absorption spectrum are used to prove that this anisotropy is induced by the molecular chain alignment, which would be really helpful in future applications in organic emission equipment. Moreover, this result is also applicable to the poly (9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(1,4-benzo-2,1',3-thiadiazole) film system.