The two most important figures of merit for particle-beam lithography are the resolution and the exposure efficiency. Electron-beam lithography allows structures with features as small as 9 nm to be fabricated, but it is proving difficult to reduce this resolution further, which is why researchers are exploring the use of ions. Now researchers at MIT and Carl Zeiss NTS have demonstrated the potential of neon ion beams for lithography.
Karl Berggren and co-workers explored how lithographic performance was influenced by three factors: the spot size of the ion beam; the volume of the interaction between the beam and the lithographic resist; and the rate at which energy is deposited by the ions as they travel through the resist material — a factor known as the stopping power.
The MIT–Carl Zeiss researchers modified a commercial helium ion microscope so that it could deliver a neon ion beam with an energy of 20 keV, and they used this beam to make gratings with line widths of just 7 nm on a silicon surface. The resist was a 16-nm-thick layer of hydrogen silsesquioxane. Moreover, they showed that the exposure efficiency was about 1,000 times better than that achieved with 30 keV electrons.
Rights and permissions
About this article
Cite this article
Written with neon beams. Nature Nanotech (2011). https://doi.org/10.1038/nnano.2011.204
Published:
DOI: https://doi.org/10.1038/nnano.2011.204
