Inspection Apparatus, Inspection Method and Manufacturing Method

摘要

A product structure (407, 330′) is formed with defects (360-366). A spot (S) of EUV radiation which is at least partially coherent is provided on the product structure (604) to capture at least one diffraction pattern (606) formed by the radiation after scattering by the product structure. Reference data (612) describes a nominal product structure. At least one synthetic image (616) of the product structure is calculated from the captured image data. Data from the synthetic image is compared with the reference data to identify defects (660-666) in the product structure. In one embodiment, a plurality of diffraction patterns are obtained using a series overlapping spots (S(1)-S(N)), and the synthetic image is calculated using the diffraction patterns and knowledge of the relative displacement. The EUV radiation may have wavelengths in the range 5 to 50 nm, close to dimensions of the structures of interest.

主权项

1. An inspection apparatus for identifying defects in a product structure, the apparatus comprising:
a radiation source and an image detector in combination with an illumination optical system, wherein the radiation source and the illumination optical system are arranged to provide a spot of radiation on the product structure, and wherein the image detector is arranged to capture at least one diffraction pattern formed by said radiation after scattering by the product structure, and wherein the inspection apparatus further comprises a processor arranged
(i) to receive image data representing said captured diffraction pattern,(ii) to receive reference data describing a nominal product structure,(iii) to calculate from the image data at least one synthetic image of the product structure and(iv) to compare data from the synthetic image with the reference data to identify a defect in the product structure.