Fabrication of poly(9,9'-dioctylfluorene)-based nano- and microstructures by proton beam writing

Maeyoshi, Yuta*; Takano, Katsuyoshi*; Asano, Atsushi*; Marui, Hiromi*; Omichi, Masaaki*; Sato, Takahiro; Kamiya, Tomihiro; Ishii, Yasuyuki; Okubo, Takeru; Koka, Masashi; Kada, Wataru; Sugimoto, Masaki; Nishikawa, Hiroyuki*; Saeki, Akinori*; Seki, Shu*

A relation between the fluence and the beam-induced chemical reaction in poly(9,9'-dioctylfluorene), PFO, films has been investigated to fabricate PFO-based nano-micro structures using Proton Beam Writing, PBW. In this investigation, we observed that the cross-linking reaction in PFO occurred without a cross-linking agent using PBW. Furthermore, not only the surface morphology but also structure and shape on PFO films were changed from nano-meter to micro-meter size by controlling the fluence of proton beam irradiation on the basis of the investigation. Consequently, the structure of the arabic numbers was successful fabricated as three-dimensional PFO structures with the aspect ratio of 12 at the fluence of 3.5 10 ions/m by PBW.