A photolithography mask having a subresolution alignment mark window

摘要

A photolithography mask having a visible-light-opaque film disposed on a surface of a transparent substrate. The film includes at least one opening that defines an image of a circuit feature, and a window for viewing an alignment mark on an associated wafer. The window has an array of openings in the opaque film, wherein each opening is of a dimension which is substantially below that of the opening defining the image of the circuit feature. Further, a method of aligning the above photolithography mask with a wafer to be patterned. The method comprises the steps of looking through the window of the mask to view the alignment mark on the wafer and positioning the alignment mark of the wafer within the window of the mask.