Mitsui Chemicals Sets up Production Facilities for CNT Pellicles to Be Used in Next-Gen EUV Lithography

MITSUI PELLICLE™ is a dustproof photomask cover for the photolithography process, which sees semiconductor wafers exposed to light in order to etch circuit patterns. The pellicle is designed with optimal thickness to allow for high transmittance, and its membrane material is selected to provide light resistance against each exposure wavelength used. Use of MITSUI PELLICLE™ keeps photomasks clean and helps improve semiconductor productivity. Since beginning pellicle sales in 1984, Mitsui Chemicals has continually strived to improve its pellicles and their quality in line with the downsizing of semiconductors.

ICT, essential to solving social issues, is advancing at an increasing pace – in particular the use of 5G communications, AI, IoT and big data, leading us all into an increasingly digital society. The task of processing this data falls on semiconductors, and with the requirement for these semiconductors to have high-speed processing capabilities and low power consumption, there is an increasing need for ultrafine circuit widths of 7 nanometers or less. The industry is in turn seeing rising practical adoption of extreme ultraviolet (EUV) exposure technology with a wavelength of 13.5 nanometers, suitable for forming ultrafine circuits.

Mitsui Chemicals has a business licensed by Dutch company ASML Holding N.V. for producing EUV pellicles. The company became a global industry leader in 2021 by beginning commercial production of EUV pellicles at its Iwakuni-Ohtake Works, allowing it to help meet growing demand for next-generation semiconductors.

There is particular demand growth for High NA (numerical aperture of 0.55), high-output (600W or above) lithography, which represents the next generation of EUV lithography technology. And pellicles made from new materials will be essential to withstand the harsh lithography environments required to make this technology a reality.

In order to match these innovations in exposure technology, Mitsui Chemicals has decided to establish mass production facilities as a step toward commercializing CNT pellicles that have both high EUV transmittance (92% or above) and light resistance for exposure output of over 1kW.

By adding next-gen pellicle products using CNT as the membrane material to its lineup alongside conventional EUV pellicles made with a silicon-based membrane, Mitsui Chemicals hopes to contribute to improved semiconductor performance and productivity.