Planarizing material for reverse-tone step and flash imprint lithography

Abstract

Abstract. 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, and have low viscosity and low volatility. One such unique 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 at 25°C), and low vapor pressure (0.65 Torr at 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® 100 (Molecular Imprints Inc., Austin, Texas) imprint tool. The results indicate that epoxy-Si-12 works very well as a planarizing layer for S-FIL/R.

Sequential Brush Grafting for Chemically and Dimensionally Tolerant Directed Self-Assembly of Block Copolymers

“…First, the PMMA domain is selectively etched (2:1) relative to PS using O 2 plasma (Figure 6b,c 6d). This dry lift-off pattern transfer approach, while similar to recent planarization demonstrations, 29,30,44 highlights the value of combining ALD with BCP lithography. The pattern transfer method can be easily scaled with decreasing feature sizes once a PS soft mask can be generated from the BCP pattern.…”

“…We demonstrate that the process has a large tolerance over the quality of the guiding features and that the addition of the homopolymer inks does not compromise the line roughness of the final pattern. Finally, we test the quality of the assembly by implementing a robust “dry lift-off” protocol for pattern transfer based on atomic layer deposition akin to planarization methods. , The results here should also make DSA a more accessible technique to research labs lacking direct access to custom-made polymer mats and brushes or without access to the latest e-beam or immersion lithography. While this work is still done with PS- b -PMMA, which will not extend to sub-10 nm, we anticipate that the self-healing properties on the guiding patterns and the wide process window margins developed here would be applicable to other higher-χ materials that could complement extreme ultraviolet (EUV) patterning.…”

Nanoimprinting of TiO 2 –SiO 2 photocurable materials with high titanium concentration for CF 4 /O 2 etch selectivity

“…The methodology used in the above studies is useful in conducting the work reported in this Letter. In our previous studies, fluorinated SiO 2 ‐based resist materials and eco‐friendly sugar derivative resist materials as natural compounds were developed in step and flash nanoimprint lithography [14–16]. However, little is known about nanoimprint lithography using TiO 2 –SiO 2 photocurable materials with high titanium concentration for CF 4 /O 2 etch selectivity with a pattern transferring carbon layer in nanoimprinting as a bi‐layer process.…”

Fabrication of nanostructured antibacterial film derived from oligoglucosamine in ultraviolet nanoimprint lithography using a solvent-permeable template

“…27) Then, we used and analyzed the gel permeation chromatography (HLC-8420GPC EcoSEC Elite; Tosoh) with N,N-dimethylformamide as the mobile phase. 28) Oligoglucosamine with an averaged molecular weight of 1000 was reacted with 2-acryloyloxyethyl isocyanates to add the cross-linked acryloyloxyethyl groups into the oligoglucosamine to fabricate the nanostructured antibacterial crosslinked film derived from oligoglucosamine with excellent demolding from the template. As above, oligoglucosamine was synthesized similarly to hydroxypropyl gamma-cyclodextrin.…”