Molecular glass resists for EUV lithography

The semiconductor industry requires new photoresist materials in order to operate in the sub-50 nm regime. In addition to meeting the resolution and line edge roughness requirements, these photoresists must be transparent in the extreme ultraviolet and have excellent etch resistance characteristics. This report highlights several small molecule molecular glasses, which are low molecular weight organic materials that demonstrate a glass transition temperature as well as a low tendency towards crystallization, with new architectures designed for EUV lithography. Transparency at the EUV wavelength of 13.4 nm may be enhanced by incorporation of low absorbing atoms such as C, H and Si. Rigid, asymmetric structures have been included in order to reduce crystallization and increase Tg. Studying the effects of these design characteristics across a continuum of architectures enables greater insight into the factors affecting photoresist performance.