Scatterometry system and method for generating non-overlapping and non-truncated diffraction images

A method, comprising:

• transmitting, from an illumination source, a first illumination beam and a second illumination beam;
• illuminating, with an objective lens including a central obscuration, a scatterometry target having at least two periodic structures in at least two layers with the first illumination beam at a first illumination angle and the second illumination beam at a second angle such that the scatterometry target diffracts the first illumination beam and the second illumination beam;
• and
• collecting, with the objective lens, at least one diffracted order from each of the first illumination beam and the second illumination beam, wherein the at least one diffracted order from each of the first illumination beam and the second illumination beam are located entirely within a portion of an imaging pupil plane not blocked by the central obscuration, wherein the at least one diffracted order from each of the first illumination beam and the second illumination beam have a non-overlapping distribution in the imaging pupil plane.