Going outside of the PDK rules you risk contamination because a chip machine is a high speed ultra-accurate automated mechanical and chemical laboratory. It sp

Going outside of the PDK rules you risk contamination because a chip machine is a high speed ultra-accurate automated mechanical and chemical laboratory. It sprays extremely corrosive acids and vaporizes metals. Going a nanometer outside of the rules would send droplet or flakes of chemicals flying around at high speed. https://www.epfl.ch/research/facilities/cmi/equipment/photolithography/asml-pas-5500-350c/ https://www.epfl.ch/research/facilities/cmi/equipment/photol...