Planarizing Material For Reverse-Tone Step And Flash Imprint Lithography

Ogawa, Tsuyoshi
Takei, Satoshi
Jacobsson, B. Michael
Deschner, Ryan
Bell, William
Lin, Michael W.
Hagiwara, Yuji
Hanabata, Makoto
Willson, C. Grant
Journal Title
Journal ISSN
Volume Title

Reverse-tone Step and Flash Imprint Lithography (S-FIL/R) requires materials that can be spin coated onto patterned substrates with significant topography and that are highly-planarizing. Ideally, these planarizing materials must contain silicon for etch selectivity, be UV or thermally curable, have low viscosity, and low volatility. One such novel material in particular, a branched and functionalized siloxane (Si-12), is able to adequately satisfy the above requirements. This paper describes a study of the properties of epoxy functionalized Si-12 (epoxy-Si-12) as a planarizing layer. An efficient synthetic route to epoxy-Si-12 was successfully developed, which is suitable and scalable for an industrial process. Epoxy-Si-12 has a high silicon content (30.0 %), low viscosity (29 cP @ 25 degrees C), and low vapor pressure (0.65 Torr @ 25 degrees C). A planarizing study was carried out using epoxy-Si-12 on trench patterned test substrates. The material showed excellent planarizing properties and met the calculated critical degree of planarization (critical DOP), which is a requirement for a successful etch process. An S-FIL/R process using epoxy-Si-12 was demonstrated using, an Imprio (R) 100 (Molecular Imprints Inc., USA) imprint tool. The results indicate that epoxy-Si-12 works very well as a planarizing layer for S-FIL/R.

Tsuyoshi Ogawa, Satoshi Takei, B. Michael Jacobsson, Ryan Deschner, William Bell, Michael W. Lin, Yuji Hagiwara, Makoto Hanabata, C. Grant Willson. SPIE 7637, Planarizing Material For Reverse-Tone Step And Flash Imprint Lithography. Alternative Lithographic Technologies II, 763708 (Apr. 2010); doi:10.1117/12.846430.