Scatterometric characterization of diffractive optical elements

Diffractive optical elements offer a great way to control light beyond the capabilities of traditional refractive components. Because of the very small feature sizes, the characterization of diffractive optical elements is challenging. Using current invasive methods, such as scanning electron microscope (SEM) or atomic force microscope (AFM), the measurements are slow and potentially destructive to the element. Employing optical scatterometery, the measurements are not only fast and non-destructive but also integrable to inline control of the fabrication and replication processes. In this work we use scatterometer to determine the dimensional parameters of binary diffractive optical elements and compare the results with the parameters obtained with AFM and SEM.