Tutorial Speaker

History of Pellicles for Photomasks — Function, Materials, and Challenges

Yosuke Ono (Mitsui Chemicals, Inc.)

Biography

Yosuke Ono joined Mitsui Chemicals, Inc. in 2007 and currently serves as the Team Leader of the Next Generation EUV Pellicle Development Team within the Development Division of ICT Solution Business Sector. His expertise includes CNT structural control, thin film deposition technologies, and optical and mechanical property evaluation. Since 2015, he has been engaged in process design and reliability assessment for the practical implementation and mass production of next generation EUV pellicles.

Abstract

This tutorial provides an accessible introduction to pellicles, which serve as essential components for protecting photomasks from particle contamination while maintaining imaging performance. It reviews how pellicle technology has evolved from the g-line and i-line generations through DUV and finally to EUV lithography. This overview highlights how optical requirements, cleanliness standards, pellicle materials, and reliability expectations have shifted as lithography has progressed. The tutorial then introduces recent advances in CNT-based pellicles for EUV, outlining the key challenges that remain.