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.
“For the mother who has opted to stay home, the question remains: Having perfected her role as a caretaker, can she abdicate control to less practiced individuals? Having put all her identity eggs in one basket, can she hand over the basket freely? Having put aside her own ambitions, can she resist imposing them on her children? And having set one example, can she teach another?”
—Melinda M. Marshall (20th century)
“True balance requires assigning realistic performance expectations to each of our roles. True balance requires us to acknowledge that our performance in some areas is more important than in others. True balance demands that we determine what accomplishments give us honest satisfaction as well as what failures cause us intolerable grief.”
—Melinda M. Marshall (20th century)