[citation][nom]gilgamex[/nom]I think it's because the wafer is spun through all sorts of production phases, the circular shape of it allows the aerodynamics of it to be consistent leaving little margin for error.[/citation]
Ignore this is completely wrong, and honestly a guess, "Silicon wafers are grown by using the Czochralski, in which a 'seed crystal' is rotated in a bath of hot molten silicon. As the seed crystal rotates, silicon atoms stick to crystal with a specific orientation that forms a crystal lattice. Eventually, this crystal becomes significantly large and forms a ingot weighing several tons. Because the crystal was rotating, the edges appear form a circle, not unlike spinning a popsicle stick in a thick syrup." found this on a website