Embodiment of The present invention includes a scatterometry targets are utilized in determining the alignment between the substrate layers. Target sequences, are formed on a substrate, and a plurality of target cells. Each cell has two layers including a periodic feature, The layers are configured such that the upper layer is arranged above the lower layer, periodic upper layer features are offset with respect to the periodic feature of the lower layer, and / or are configured so as to have a periodic features different from the pitch of the lower layer. These pitches are arranged so as to generate a periodic signal when the target is exposed to an illumination source. The target further comprises a disambiguation for features that are arranged in between cells, ambiguity removal features, resolve ambiguities caused by the periodic signal generated by the cell when exposed to the illumination source It is configured to.
.FIELD 2 (g)