[15a-423-1~9] CS.4 7. Code-sharing Session: Beam Technology and Nanofabrication

[15a-423-1] Observation of fluorescence moire fringe for imprint alignment

〇Eri Kikuchi¹, Yota Ishito¹, Shinya Matsubara², Takahiro Nakamura¹, Masayuki Abe², Masaru Nakagawa¹ (1.Tohoku Univ., 2.Asahi Kasei Co.)

Keywords:nanoimprinting, alignment, fluorescence

n ultraviolet nanoimprinting, there is an issue in alignment that alignment marks of a silica mold are difficult to observe because of little difference in refractive index between silica and UV-curable resin. The purpose of this study is to enable mold alignment marks to be visualized under an in-liquid condition. We could observe mold and substrate alignment marks with a fluorescence liquid inserted between mold and substrate surfaces by fluorescence microscopy. We further confirmed that fluorescence moiré fringes were generated by superposing a periodical mold bar-array on another substrate bar-array with different periodicity. We principally demonstrated that course alignment with cross-bars could be detected by fluorescence moiré interference fringes. We gave a possibility that fluorescence moiré interference fringes will be available for fine alignment. We will discuss advantages of the imprint alignment with fluorescence UV-curable resins: (1) a metal and high-reflective-index material layer to modify silica molds is unnecessary. (2) Alignment can be carried out concomitantly with monitoring a residual layer thickness between mold and substrate surfaces using fluorescence intensity.