30, 20, and 10 Years Ago in OPN

“As the VLSI (very-large-scale integration) industry demands cameras that can produce images of ever greater resolution, lithographic technology has responded by developing lenses capable of diffraction-limited imaging … As we look forward, we see that quarter-micron lithography will be needed for mass production well before the end of the decade and tenth-micron lithography sometime after. It is believed that ultraviolet step-and-repeat cameras using phase masks will be extended to 0.3 μm, perhaps slightly below, but with restrictions in pattern geometries.”