EUV Multi-Patterning

EUV lithography's shorter 13.5nm wavelength directly resolves finer pitch than 193nm immersion lithography can achieve in a single exposure, reducing, though not always fully eliminating, the need for multi-patterning at a given target pitch relative to what 193nm-based patterning alone would require. Many advanced-node layers still combine EUV with some degree of multi-patterning for the very finest pitches, since even EUV's shorter wavelength has its own practical resolution limit that the most aggressive pitch targets can still exceed without additional patterning assistance.