EUV lithography
Beginner
Printing chip patterns with a special ultraviolet light. Its waves are much shorter than those of ordinary light, so it can print smaller shapes.
Novice
Lithography with extreme ultraviolet light of 13.5 nm wavelength, about fourteen times shorter than the 193 nm deep-ultraviolet light used before it. The light comes from tin droplets hit by a laser, and because air and glass absorb it, it travels in a vacuum and is focused with mirrors.
Expert
Uses reflective masks made of alternating molybdenum and silicon layers and all-mirror optics. Current tools have a numerical aperture of 0.33; high-NA tools reach 0.55 by using anamorphic optics (different magnification in the two directions), which halves the exposure field to 26 × 16.5 mm.
Explained in After tapeout (Extras).
See also: Photolithography, Numerical aperture (NA).