Patterning 100 nm features using deep-ultraviolet contact photolithography

The extension of contact photolithography to pattern features at the 100 nm level, and below, is described. Isolated lines, nested L’s, and gratings with 100 nm linewidths are patterned using a conformable embedded-amplitude mask, a trilayer resist stack on the substrate, and a deep-ultraviolet radiation source having a wavelength of λ∼220 nm. A broad exposure latitude of ±21% for a linewidth control of ±10% is measured. Preliminary calculations indicate a practical resolution limit for the lithographic process. The patterning process is reliable and repeatable.