So essentially, these chips are made by shining the design through a mask over a silicon disc coated with photoactive chemicals and then chemically processed to

So essentially, these chips are made by shining the design through a mask over a silicon disc coated with photoactive chemicals and then chemically processed to make that design "stick" depending on what parts were illuminated and what parts were not, much like old school photography. There's no physical etching going on, its a chemical process where light is used to "activate" certain parts of a coating. The wavelength, or the color of the light here limits how much minified image we can shine and currently the Extreme ultraviolet lithography(EUV) is the state of the art where they use ultraviolet light with 13.5nm wavelength. As different materials behave differently under different light wavelengths, EUV requires different process to shine the mask over the silicon disk. One major difference from the previous processes is that in EUV lithography they use mirrors instead of lenses to direct the light. So far, it's only the European manufacturer ASML who managed to perfect this process for mass production.