Sequential infiltration synthesis improves EUV lithography
IMEC is presenting its use in multiple papers at this week’s 2019 SPIE Advanced Lithography Conference.
SIS is an existing technique, used in directed self-assembly (DSA) in which the photoresist is infiltrated with an inorganic element to make it harder and more robust, thereby enhancing the patterning performance in a variety of ways.
It comes at the cost of an additional step but during a full pattern transfer in a TiN layer, imec observed a improvement of 60 percent for intrafield local critical dimension uniformity (LCDU) and 10 percent for line edge roughness compared to a reference process. These patterning enhancements are inherent properties of SIS. Also, the number of nanobreaks – a typical stochastic nano-failure – is reduced by at least one order of magnitude. Results were confirmed in an industrial use case, showing reduced defectivity in a logic chip with a 20 percent smaller tip-to-tip critical dimension at a similar LCDU as a standard EUVL process.
The work was performed in collaboration with ASM and ASML.
“This is a great example of how the integration of knowledge and combined efforts from multiple domains and ecosystem partners will enable a path to scale to N3 and beyond,” said Greg McIntyre, director of advanced patterning at IMEC, in a statement.
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