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 °C), and low vapor pressure (0.65
Torr @ 25 °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 ImprioR
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.