A marker structure on a substrate includes line elements and trench
elements, the line elements and trench elements each having a length in a
first direction and being arranged in an alternating repetitive sequence
in a second direction perpendicular to the first direction, the
alternating repetitive sequence having a sequence length, the marker
structure having at least one pitch value, the at least one pitch value
being the sum of a line width of one line element and a trench width of
one trench element. A width of the line elements varies over the sequence
length of the marker structure between a minimum line width value and a
maximum line width value, while a width of the trench elements likewise
varies over the sequence length of the marker structure between a minimum
trench width value and a maximum trench width value. A duty cycle of a
pair of a line element and an adjacent trench element is substantially
constant over the sequence length of the marker structure. Thus, the
pitch value varies from a minimum pitch value to a maximum pitch value
over the sequence length.