Background: In the semiconductor industry, infrared light can be used to characterize materials such as thin films and periodic trench structures. By measuring the reflectance of light from the surface of a semiconductor wafer, the index of refraction (n) and the extinction Coefficient (k) can be determined via the Forouhi-Bloomer dispersion equations. The reflectance from the infrared light can also be used to determine the critical dimension, depth, and sidewall angle of high aspect ratio trench structures.
Question: What equations are used to figure out the index of refraction and extinction Coefficient?
Answer:<extra_id_0>.
<extra_id_0> Forouhi-Bloomer dispersion<extra_id_1>