 Self-aligned quadruple patterning (SAQP) is already the established process to be used for patterning fins for 7 nm and 5 nm FinFETs.With SAQP, each patterning step gives a critical dimension uniformity (CDU) value in the sub-nanometer range (3 sigma).Among the four logic/foundry manufacturers, only Intel is applying SAQP to the metal layers, as of 2017.