What is photolithography?
Photolithography is one of the important processes in the production of integrated circuits (ICs or chips). Simply say, it is the process of copying a circuit pattern on a substrate by using the photomask and photoresist.
The substrate will be painted on silicon dioxide insulating layer and photoresist. The photoresist can be dissolved easily with a developer after being exposed to UV light, after dissolver and etched, the circuit pattern will be left on the substrate.
What is Photoresist? Why must 500nm UV wavelength blocks-off?
Photoresist is combined with resins, solvents and additives. The light sensitive range of photoresist is 200nm-500nm. Therefore, many semiconductors laboratory will adopt yellow light which blocks off 500nm UV wavelength to prevent the photoresist overexposed or prematurely exposed situations.
