Hello Everyone: I am trying to perform characterization on diamond films in terms of thickness and I having some issues measuring the thickness of the films across the wafer. The main problem that I am having is that I do not know the index of refraction of the diamond film. I was wondering if someone knows about any method or company able to measure the value of n for a specific material. So far, I have tried the elipsometer but since I do not know the thickness and neither the index of refraction I am having wrong measurements. I will appreciate any idea or suggestion. Thanks in advance; Eric J. Correa Rivera Graduate Student Mechanical Engineering University of Illinois at Urbana Champaign