13 March 2015 Low-energy electron (0-100eV) interaction with resists using LEEM
Author Affiliations +
Extreme Ultra Violet (EUV) lithography is a next generation lithographic technique using 13.5 nm wavelength light (91.7eV photon energy) to define sub-20 nm features. This high energy radiation generates lower energy electrons (LEEs) after being absorbed. The mean free path of LEEs increases rapidly below ca. 30 eV allowing them to migrate several nanometers from their point of origin. As LEEs can still have sufficient energy to react with the surrounding resist, this may give rise to pattern blurring, posing a challenge for sub 10 nm features. Here, we introduce Low Energy Electron Microscopy (LEEM) as an extremely useful technique to investigate the interactions of LEEs with EUV resists. Using LEEM we can expose the resist with precise electron energies and doses. We also report the initial results of LEE exposures on poly(methyl methacrylate) PMMA. We have studied the LEE-PMMA interaction depth as a function of electron energy; a distinct exposure threshold is found at ~15 eV, below which the resist responds only very weakly to electron exposure.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
A. Thete, A. Thete, D. Geelen, D. Geelen, S. Wuister, S. Wuister, S. J. van der Molen, S. J. van der Molen, R. M. Tromp, R. M. Tromp, "Low-energy electron (0-100eV) interaction with resists using LEEM", Proc. SPIE 9422, Extreme Ultraviolet (EUV) Lithography VI, 94220A (13 March 2015); doi: 10.1117/12.2085369; https://doi.org/10.1117/12.2085369

Back to Top