EUV Lithography

EUV (extreme ultraviolet) lithography is the chip-patterning technique that uses light with a wavelength of just 13.5 nanometers to print the finest circuit features on a wafer. Because that wavelength is roughly fourteen times shorter than the deep-ultraviolet light it replaces, EUV can resolve patterns far smaller than older tools, enabling the 7nm, 5nm, 3nm, and 2nm processes used for cutting-edge logic, including the most advanced Bitcoin mining ASICs.

How the light is made

EUV light does not occur in convenient lasers, so it is generated on demand. Inside the scanner, around 50,000 droplets of molten tin per second are fired into a vacuum and hit by two pulses of a high-power CO2 laser: a pre-pulse flattens each droplet, and the main pulse vaporizes it into a plasma that radiates 13.5nm light. Because air and ordinary glass absorb EUV, the entire optical path runs in vacuum and uses precision multilayer mirrors rather than lenses.

Why it matters for mining silicon

Before EUV, printing sub-7nm features required stacking many exposure-and-etch passes, which is slow and costly. A single EUV exposure can replace several of those steps, improving yield and cost at the leading edge, the same leading edge that drives down joules per terahash. ASML is currently the only company that builds and sells EUV scanners, supplying TSMC, Samsung, and Intel.

EUV lithography is what makes today's FinFET and GAAFET nodes manufacturable, reducing the reliance on multi-patterning at critical layers.