The authors fabricated test wafers to evaluate the detection performance of the new methodology. The illumination light at a wavelength of 1100 nm was used. The light source used was a halogen lamp, and the narrow band of 1100-nm wavelength obtained using an interference filter was applied. Here, is 0.00003, and the penetration depth is approximately 3 mm, as shown in Fig. 5. The sensitivity of the image sensor chip is, however, very low at this wavelength; hence, the authors used a cooled camera to ensure an excellent SNR. The camera used was Hamamatsu ORCA-AG. In addition, other wavelengths, such as 850, 800, 700, 546 (e-line), 436 (g-line), and 405 (h-line) nm, were also investigated.