What is Photomask?

Photomask is a glass or quartz coated with chrome on one side. Mask pattern is generated precisely by electronic beams or lasers which convert the design of integrated circuit or main chip onto mask. Being exposed, the pattern is etched with chrome, and the reticle is performed. Photographically, the mask transfers circuit patterns entirely onto semiconductor wafer. A wafer is composed of 15 to 30 retrofit masks normally.