In order to determine whether an
exposure apparatus is outputting the correct
dose of
radiation and its
projection system is focusing the
radiation correctly, a test pattern is used on a
mask for printing a specific marker onto a substrate. This marker is then measured by an inspection apparatus, such as a
scatterometer, to determine whether there are errors in focus and
dose and other related properties. The test pattern is configured such that changes in focus and
dose may be easily determined by measuring the properties of a pattern that is exposed using the
mask. The test pattern may be a 2D pattern where physical or geometric properties, e.g.,
pitch, are different in each of the two dimensions. The test pattern may also be a one-dimensional pattern made up of an array of structures in one dimension, the structures being made up of at least one
substructure, the substructures reacting differently to focus and dose and giving rise to an exposed pattern from which focus and dose may be determined.