OVERLAY MARK FOR EXPOSURE ENERGY AND FOCUSING

摘要

An overlay mark for detecting focus and exposure energy during an alignment process for forming a pattern of a semiconductor device is disclosed. The overlay mark includes an inner box and an outer box to concurrently measure exposure energy and focus, wherein, the changes of the exposure energy and the focus are respectively represented by phase shift between the inner and outer boxes in X-axis and Y-axis, the X-axis and the Y-axis representing phase shift respectively to indicate the exposure energy and the focus.