Fluorinated polymethacrylates as highly sensitive non-chemically amplified e-beam resists

Abstract

In an effort to improve upon the sensitivity of commercial non-chemically amplified e-beam resists, four polyacrylates functionalized with α-CF 3 and/or CH 2 CF 3 alkoxy substituents were studied. The α-CF 3 substituent is known to increase backbone-scission efficiency while simultaneously eliminating acidic out-gassing and cross-linking known to occur in α-halogen substituted polyacrylates. Contrast curves for the polymeric α-CF 3 acrylates, generated through e-beam exposure, showed the resists required an order of magnitude less dose than the current industry-standards, PMMA and ZEP. The fundamental sensitivity of these materials to backbone scissioning was determined via 60 Co γ-ray irradiation. The chain scissioning, G(s), and cross-linking, G(x), values calculated from the resulting change in molecular weight demonstrated that all fluorinated resists possess higher G(s) values than either PMMA or ZEP and have no detectable G(x) values. Utilizing e-beam and EUV interference lithographies, the photospeed of PMTFMA was found to be 2.8x and 4.0x faster, respectively, than PMMA.

Organoiodine Functionality Bearing Resists for Electron-Beam and Helium Ion Beam Lithography: Complex and Sub-16 nm Patterning

“…32 The developed fluorinated polyacrylate was found to be more sensitive than the conventional resists ZEP and PMMA. 32 Guo and group reported a fluorinated silsesquioxane-based photoresist as potential materials for ultraviolet nanoimprint lithography. 33 The incorporation of fluorine into the resist backbone has been successfully explored for developing a high performing single-layer resist for 157 nm lithography.…”

“…Among several approaches that have been adopted by different research groups across the globe to improve resist performance in terms of sensitivity and resolution, incorporation of inorganics or organohalo-functionality into resist architecture has been very successful. − Integration of inorganics into a resist network has helped in improving resolution, etch resistance, and sensitivity. , In recent times, metal–organic materials (both molecular and macromolecular) have been found to be quite promising resist systems in the current scenario of advanced IC technology. − Similarly, incorporation of halogens into the resist matrix has been very successful in developing high performance resists with improved properties. To mention a few, Wilson and co-workers reported the positive impact of the inclusion of fluorinated functionality in resist architecture on the backbone-scission efficiency and sensitivity . The developed fluorinated polyacrylate was found to be more sensitive than the conventional resists ZEP and PMMA .…”

“…To mention a few, Wilson and co-workers reported the positive impact of the inclusion of fluorinated functionality in resist architecture on the backbone-scission efficiency and sensitivity . The developed fluorinated polyacrylate was found to be more sensitive than the conventional resists ZEP and PMMA . Guo and group reported a fluorinated silsesquioxane-based photoresist as potential materials for ultraviolet nanoimprint lithography .…”