An overlay mark for determining the relative shift between two or more
successive layers of a substrate is disclosed. The overlay mark includes
at least one test pattern for determining the relative shift between a
first and a second layer of the substrate in a first direction. The test
pattern includes a first set of working zones and a second set of working
zones. The first set of working zones are disposed on a first layer of
the substrate and have at least two working zones diagonally opposed and
spatially offset relative to one another. The second set of working zones
are disposed on a second layer of the substrate and have at least two
working zones diagonally opposed and spatially offset relative to one
another. The first set of working zones are generally angled relative to
the second set of working zones thus forming an "X" shaped test pattern.