Inspection Apparatus, Inspection Method and Manufacturing Method

摘要

An inspection apparatus is provided for measuring properties of a non-periodic product structure (500′). A radiation source (402) and an image detector (408) provide a spot (S) of radiation on the product structure. The radiation is spatially coherent and has a wavelength less than 50 nm, for example in the range 12-16 nm or 1-2 nm. The image detector is arranged to capture at least one diffraction pattern (606) formed by said radiation after scattering by the product structure. A processor receives the captured pattern and also reference data (612) describing assumed structural features of the product structure. The process uses coherent diffraction imaging (614) to calculate a 3-D image of the structure using the captured diffraction pattern(s) and the reference data. The coherent diffraction imaging may be for example ankylography or ptychography. The calculated image deviates from the nominal structure, and reveals properties such as CD, overlay.

主权项

1. An inspection apparatus for measuring properties of a product structure, the apparatus comprising:
a radiation source; an illumination optical system; and an image detector in combination with the illumination optical system, wherein the radiation source and the illumination optical system are arranged to provide a spot of radiation on the product structure, the radiation having a wavelength less than 50 nm, 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 assumed structural features of the product structure and (iii) to calculate from the image data and the reference data one or more properties of the product structure.