END POINT DETECTION METHOD

摘要

END POINT DETECTION METHOD The clearing point of photoresist development is detected automatically by illuminating the developing photoresist surface with intense monochromatic light. Interfering reflection from the resist-substrate interface and the fast eroding and slow eroding resist surfaces produces fast and slow oscillatory signals. These signals are processed to produce a logical output indicative of the cessation of the fast oscillations in the presence of the continuing slow oscillations signaling the clearing point of development.