Photolithography (printing with light): in the 1950s Jay Lathrop covered germanium with photoresit chemicals that would disappear upon exposure to light. Using an inverted microscope a large image (photgraphic mask) could then be projected in minature down onto the photoresist chemicals. Once these chemicals were washed away a pattern of holes would remain (etching) would remain matching the mask. This allowed very small transistors to be printed1.


Miller, C. Chip War: The Fight for the World’s Most Critical Technology. (Scribner, New York, 2022).

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