Figure 3
From: Lens-free reflective topography for high-resolution wafer inspection
Image reconstruction fidelity based on the illumination pattern. (a–d) Reconstructed image \({O}_{{\text{r}}}\) and probe function \({\psi }_{{\text{r}}}\), respectively, without a diffuser. (b) and (c) show the magnified images of the regions within the red boxes in (a) and (b), respectively. (e–h) Reconstructed image and probe function using a weak diffuser. (i–l). The same as (e–h), but with a strong diffuser. The array sequence for all images follows as (a–d). All images are normalized for comparison. As the illumination pattern becomes more complex (d, h, and l), the FOVs of the images expand (a, e, and i) and their resolutions improve (c, g, and k). (m). Line plot graph of element 1 in group 7 of images (b), (f), and (j) (denoted by the white dotted line). (n) Line plot graph of element 1 in group 8 of images (c), (g), and (k) (denoted by the white dotted line). (o). Graph comparing the contrast of line plots for (m) and (n). For group 8 patterns, a significant contrast value of 0.4 is observed when a strong diffuser was used.
