Tutorial Speaker

History And Challenges Of Photoresist Material Development

Kei Yamamoto (FUJIFILM Corporation)

Biography

Kei Yamamoto received his Master’s degree in Polymer Chemistry from Tokyo Institute of Technology, Japan, in 2004. He then joined FUJIFILM, where he has been engaged in the development of advanced photoresist materials, including ArF immersion resists. He has also contributed to the development of KrF, EUV, and EB resists.

He is currently an R&D Manager at the Electronic Materials Development Center of FUJIFILM, where he is responsible for research and development of E-Beam resist technologies.

His main fields of research include polymer chemistry, advanced photoresist materials, ArF immersion, KrF and EUV resists, and E-Beam resist technologies.

Abstract

In accordance with Moore’s Law, continuous scaling of semiconductor devices has required tighter pitch sizes and smaller pattern features in lithography over the past several decades. Photoresist materials have played an important role in enabling this progress, evolving in close collaboration with advances in exposure tools, mask technologies, and pattern transfer processes.
In the early stages of optical and electron-beam (EB) lithography, photoresist development primarily focused on achieving sufficient sensitivity and resolution to meet throughput and manufacturability requirements. As critical dimensions (CD) were aggressively reduced, however, additional challenges emerged, including stochastic effects such as shot noise, line edge and line width roughness, pattern collapse, and limited etch durability. These issues have driven the development of chemically amplified resists and material innovations tailored for ArF, KrF, EB, and EUV lithography.
More recently, the introduction of advanced exposure systems, such as multi-beam electron-beam writers and EUV lithography, has shifted material requirements toward higher exposure doses, improved local CD uniformity, enhanced resolution capability, and superior process stability. At the same time, photoresist materials must balance increasingly complex trade-offs among sensitivity, resolution, stochastic performance, and etch resistance, making material design more challenging than ever.
This paper reviews the development history of photoresist materials across multiple lithography generations, discusses key technical challenges that have shaped material development, and provides perspectives on the future directions for photoresist technologies.

Keywords: Photoresist, Chemically Amplified Resist (CAR), Electron-beam Lithography, EUV Lithography