Method for detecting malfunction in photolithographic fabrication track

摘要

A malfunction in a photolithographic fabrication track is detected by applying photoresist to a semiconductor wafer, and exposing the wafer to substantially identical light images in multiple locations using a stepping printer. The light images are defined by an optical reticle and include a plurality of lines or other features that are spaced from each other at approximately the resolution limit of the printer. Developer is applied to the wafer to produce visible images corresponding to the light images. The visible images function as diffraction gratings which reflect light from the wafer. The visible images are inspected optoelectronically or manually. A malfunction is determined to exist if the visible images are not substantially identical.