Electron Beam Resist Performance
Due to the scission efficiency generally being an order of magnitude higher than the crosslinking efficiency, most polymers used for positive tone electron beam lithography will crosslink (and therefore become negative tone) at doses an order of magnitude than doses used for positive tone exposure. Such large dose increases may be required to avoid shot noise effects.
A study performed at the Naval Research Laboratory indicated that low-energy (10–50 eV) electrons were able to damage ~30 nm thick PMMA films. The damage was manifest as a loss of material.
- For the popular electron-beam resist ZEP-520, a pitch resolution limit of 60 nm (30 nm lines and spaces), independent of thickness and beam energy, was found.
- A 20 nm resolution had also been demonstrated using a 3 nm 100 keV electron beam and PMMA resist. 20 nm unexposed gaps between exposed lines showed inadvertent exposure by secondary electrons.
- Hydrogen silsesquioxane (HSQ) is a negative resist that is capable of forming sub-30 nm lines in very thin layers, but is itself similar to porous, hydrogenated SiO2. It may be used to etch silicon but not silicon dioxide or other similar dielectrics.
Read more about this topic: Electron Beam Lithography
Famous quotes containing the words beam, resist and/or performance:
“How can one beam alone support a house?”
—Chinese proverb.
“The general review of the past tends to satisfy me with my political life. No man, I suppose, ever came up to his ideal. The first half [of] my political life was first to resist the increase of slavery and secondly to destroy it.... The second half of my political life has been to rebuild, and to get rid of the despotic and corrupting tendencies and the animosities of the war, and other legacies of slavery.”
—Rutherford Birchard Hayes (1822–1893)
“Tennis is more than just a sport. It’s an art, like the ballet. Or like a performance in the theater. When I step on the court I feel like Anna Pavlova. Or like Adelina Patti. Or even like Sarah Bernhardt. I see the footlights in front of me. I hear the whisperings of the audience. I feel an icy shudder. Win or die! Now or never! It’s the crisis of my life.”
—Bill Tilden (1893–1953)