Material World: The Six Raw Materials That Shape Modern Civilization

by Ed Conway

Quite how these mirrors are made is yet another closely guarded trade secret, but according to Zeiss, they are ground down from blocks weighing 50 kilograms, and robots are used to polish and correct the outer layer with ion beams. Suffice it to say, they are, according to one ASML engineer, “probably the smoothest man-made structures in the universe.” If you blew one of them up to the size of the United States, the biggest bump would be less than half a millimetre high. Having bounced off a staircase of these mirrors, the EUV light in all its 13.5 nanometre glory hits the wafer and etches that intricate design on to it. There is more than a whiff of science fiction about all of this—astoundingly perfect silicon wafers being manipulated by mind-bogglingly flat pieces of glass—yet there is nothing fantastical about it at all. And here at the heart of the silicon supply chain is that very same company that produced the glass in those binoculars the British government secretly traded for rubber during the First World War.