We describe a polymethylmethacrylate (PMMA) bilayer system which provides a simple high-resolution resist for the research and development of structures smaller than ∼0.2 μm. Intermixing between the two resist layers is avoided by the use of a weak solvent, xylene, as the solvent of the upper PMMA layer. Metal lines as narrow as 30 nm have been fabricated for electron-transport studies. Much larger features can be produced with deep-ultraviolet exposure, which facilitates electrical contact to the ultrasmall structures.
No takes yet. Share an insight, caveat, or question.
Rooks et al. (1987) studied this question.