Aqueous materials for advanced lithography (Conference Presentation)

EMD Performance Materials provides a broad material portfolio for photolithography, Chemical Shrink and EUV Rinse materials are two categories of aqueous materials enabling advanced patterning. Chemical Shrink materials generate an additional layer on the surface of photoresist pattern through chemical/physical interactions, resulting in finer trench or hole structures. The technique helps IC manufacturers improve process margin and reduce cost of ownership by relaxing the requirements for lithography. EMD has been engaged in development of the technology for over two decades, and introduced materials for multiple generations of lithography. The first generation Chemical Shrink material, AZ® R200 was commercialized for i-line and KrF applications around 2000. From then on, several commercial platforms were released targeting for ArF, ArF-immersion, and ArF NTD (Negative Tone Development) photoresists. Shrink amount depends on the material platforms and photoresists, it can be controlled from several nm to 100 nm with the process conditions, mainly shrink bake temperature. Well-controlled through-pitch proximity is one of the key advantages of the technique as well. Chemical shrink process is a straightforward and well-established in-track process. Not only smaller pattern sizes are achieved, effective DOF (Depth of Focus) is improved, but also surface smoothing of photoresist is expected. Rinse materials are a unique offering from EMD to alleviate capillary force hence mitigate pattern collapse in very fine photoresist pattern through reducing surface tension with novel surfactants. Based on the knowledge and know-hows learned during the development of rinse materials for ArF and ArF immersion lithography processes in the past decades, new material platforms have been developed to extend the technique to meet the ever more critical requirements in EUV lithography. AZ® Extreme 10 was commercialized as the world first rinse material dedicated for EUV lithography, designed for L/S (Line and Space) pattern of 22nm hp patterning. To further improve the compatibility with the latest EUV photoresists for finer pattern, 18nm hp and beyond, AZ® SPC-708 is newly commercialized in 2018. It is expected that AZ® SPC-708 helps reduce photoresist residues during development process in addition to its function of collapse mitigation. EMD Performance Materials is committed to providing novel solutions to confront the increasing technical challenges in advanced patterning.