Plasma etching of “High Chi” block copolymers

Published : 19 December 2016

For the sub-10nm nodes, several emerging lithography techniques are under evaluation to achieve patterns with higher density and resolution. Leti has already demonstrated the potential of the lithography based on block copolymer with PS-b-PMMA system (pitch 40nm). However, for achieving patterns with even more resolution, new materials called “high chi” are being studied. Thanks to the Arkema-Leti partnership, these new materials (pitch<20nm) are available at Leti, but many challenges have to be overcome in order to demonstrate the possibility to use them in microelectronic applications, such as their transfer by plasma etching. Due to the small targeted dimensions, the candidate will face several technical challenges. Thus, his/her mission will be to: - Propose innovative etching solutions by using for example the new functionalities of the last-generation etching tool available at Leti - Propose a methodology for the chemical and morphological characterization of these materials - Understand the etching mechanism involved using XPS, FTIR, STEM, EDX analysis... - Compare the different approach of block copolymers’ self-assembly (integration, impact of the hard mask used and the self-assembly defects on etching…) - Identify the best process flow in order to target one application with electrical results as a final goal

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