Abstract: A photomask includes a substrate having a transparent substrate, a mask pattern positioned on a surface of the transparent substrate, a transparent electrostatic discharge (ESD) ring positioned on the surface of the transparent substrate and surrounding the mask pattern, a pellicle covering over the mask pattern, and a mounting adhesive used for sticking the pellicle on the transparent electrostatic discharge ring. The transparent electrostatic discharge ring is utilized to examine a binding condition between the pellicle and the transparent substrate and to suppress an electrostatic discharge.

Abstract: A method for monitoring dosage/focus/leveling is provided. A control wafer is provided and divided into several regions. Five of the regions near the center of the wafer are used to monitor normally. Other regions are used as dummy shots. When a situation of a stepper changes greatly, the dosage/focus/leveling of the control wafer is monitored using the dummy shots. In monitoring exposure dosage, the middlemost region is monitored. One of the five regions, which is the most central, is exposed with a low exposure energy to enhance sensitivity of critical dimension versus energy. Many points with small areas are developed in the centermost region to take sufficient samples. Since the developed points are close, effects from the nonuniformity of development and from the nonuniformity of the photoresist layer are prevented. In focus/leveling monitoring, a curve diagram of exposure dosage versus critical dimension is provided. An exposure parameter is taken at a range of the curve with a large slope.