FOCUSING METHOD OF EXPOSURE EQUIPMENT HAVING AUTOMATIC FOCUS SYSTEM

摘要

PURPOSE: A focusing method of exposure equipment having an automatic focus system is provided to guarantee excellent patterning in performing an exposure process, by easily determining whether a foreign substance or particle is on a stage, to make a semiconductor wafer maintain a stable focus. CONSTITUTION: A plurality of lights for detecting a focus are transferred to a semiconductor wafer. Reflective lights reflected on the surface of the semiconductor wafer are detected. If at least one reflected light exceeding a value of a predetermined range among the detected reflective lights is recognized in the automatic focus system, an exposure process is stopped.