The materials challenge in diffraction-unlimited direct-laser-writing optical lithography
J. Fischer, G. von Freymann, and M. Wegener
Adv. Mater. 32, 3578 (2010)
- Date: 24.8.2010
Using a novel photoresist (composed of pentaerythritol triacrylate and isopropyl thioxanthone) that favors stimulated emission depletion by a π-π* transition and using a two-color two-photon excitation scheme, 65-nm wide lines are achieved. This value is limited by parasitic two-photon absorption of the continuous-wave depletion beam. It is estimated that, without this process, line widths of 30 nm are in reach.