EUV Light Sources for Next-Gen Lithography

Since its beginnings, commercial chip manufacturing has relied on photolithography, to pattern the incredibly small features of transistors and interconnects found on modern integrated circuits (ICs). And lithography has had to find ways to enable printing of ever-smaller features, with the ongoing demand for shrinking circuit geometries. Because of the limitations imposed by optical diffraction, as the feature sizes to be printed have shrunk, the wavelength of the light used for lithographic patterning has also needed to come down. Thus, the mercury i-line (365 nm) lithography of early years gradually gave way to 248-nm (KrF excimer laser) lithography, and then to the 193-nm (ArF excimer laser) radiation used in present-day production.