One of the major concerns with nanoimprint lithography is defecivity. One source of process specific defects is
associated with template separation failure. The addition of fluorinated surfactants to the imprint resist is an effective
way to improve separation and template lifetime. This study focuses on the development of new reactive fluorinated
additives, which function as surfactants and also have the ability to chemically modify the template surface during the
imprint process and thereby sustain a low surface energy release layer on the template. Material screening indicated that
the silazane functional group is well suited for this role. The new reactive surfactant, di-(3,3,4,4,5,5,6,6,7,7,8,8,8-
tridecafluorooctyl)silazane (F-silazane) was synthesized and tested for this purpose. The material has sufficient
reactivity to functionalize the template surface and acceptable stability (and thus shelf-life) in the imprint formulation.
Addition of F-Silazane to a standard imprint resist formulation significantly improved template release performance and
allowed for significantly longer continuous imprinting than the control formulation. A multiple-imprint study using an
Imprio® 100 tool confirmed the effectiveness of this new additive.
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 Imprio<sup>R</sup>
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.