Why EUV lithography is the pacing technology of Moore's Law

Lithography projects each layer's pattern onto the wafer, and its resolution sets the minimum feature size. Roughly, resolution improves with shorter wavelength and higher numerical aperture.

From 193 nm to 13.5 nm

Deep-ultraviolet (193 nm) light, stretched with immersion and multi-patterning, carried the industry for years. Extreme-ultraviolet (EUV) at 13.5 nm now enables the smallest features in a single exposure.

Why it's hard

• EUV is absorbed by almost everything, so the whole system works in vacuum with reflective mirrors.
• The light source vaporizes tin droplets with a high-power laser tens of thousands of times per second.
• Masks, resists, and pellicles all had to be reinvented for the new wavelength.

The next step, High-NA EUV, pushes resolution further. Explore the EUV research topic for the open questions.