Most photomasks are created by etching away a thin film of light-blocking chrome from the surface of a quartz plate.

FORBES: Trick of the Light

To further hone the image, engineers use a technique called optical proximity correction, which uses oddly shaped bars, notches and other distortions that are cut into the chrome template on the quartz plate to trick light waves into making a more precise pattern (see left).

FORBES: Trick Of The Light

To further hone the image, engineers use a technique called optical proximity correction, which uses oddly shaped bars, notches and other distortions that are cut into the chrome template on the quartz plate to trick light waves into making a more precise pattern (see chart).

FORBES: Trick of the Light