Photolithography exposure

 

A procedure to remove parts of the thin film off a substrate, ultraviolet (UV) light is used to transfer a pattern from a photomask to the photoresist compound on the surface. The exposure is further engraved onto the wafer surface beneath the layer of photoresist compound through a few rounds of chemical treatments. In a complex integrated circuit; modern CMOS for instance, a wafer will go through the

 

photolithographic cycle of up to 50 times. The equipment used to executive the photolithography process is called Stepper. The time for exposure is partially determined by the sensitivity of the photoresist compound, lens aperture and other factors.