Abstract: The invention provides a photo mask with an electric discharge (ESD) protective function. The photo mask has a transparent substrate comprising quartz or glass, a patterned shielding layer located in the predetermined area of the surface of the transparent substrate, and an ESD protective layer positioned on the surface of the transparent substrate and surrounding the shielding layer. The ESD protective layer comprises a plurality of discharging peaks. The peaks aid in a neutralizing discharge reaction, which discharges harmful static electricity into the air.

Abstract: A method of measuring a misalignment. A wafer comprising an alignment mark is provided. An outer mark with a circular shape and an outer center point is formed on the wafer. An inner mark with a circular shape and an inner center point is formed within the outer mark on the wafer. Using geometric relationship according to at least three arbitrary points on the inner and the outer marks, the inner and the outer center points are obtained. A distance between the inner and the outer points are measured. The distance indicates magnitude of the exposure misalignment.