| 摘要 |
The present invention discloses a method and a system for reflective and scanning CDI for the identification of defects (4) in an actual pattern (6) of a sample (2) as compared to the desired pattern of the sample (2), comprising:
a) providing the sample (2), either blank or having the actual pattern (6), said pattern (6) comprising absorbing and/or phase-shifting materials,
b) providing a light source (8) for generating a light beam (10) for scanning the sample (2) in transmission mode or reflection mode;
c) illuminating the sample (2) with the light beam (10), preferably under an angle of 0 to 45° relative to the surface normal of the sample, thereby diffracting the light beam (10) according to the actual pattern (6) present on the sample (2);
d) detecting the diffracted light beam (11) in terms of its position related intensities with a position sensitive detector (12);
e) analyzing the detected intensities, and thereby obtaining a reconstructed diffraction image responsive to the actual pattern (6) of the sample (2);
f) calculating a predicted diffraction image of the desired pattern, preferably using Fourier or Fresnel calculations;
g) comparing the reconstructed diffraction image with the predicted diffraction image for the detection of an intensity variation deviating from the predicted diffraction image; and
h) identifying the position of the deviating intensity variation for further inspection this position of the sample (2). |
