Novel Technique for Profiling of Mirofeatures
N.R. Sivakumar, B.K.A. Ngoi, K. Venkatrishnan and B. Tan
With the growing importance of micro machining, it has become important to measure the profile of microfeatures, in order to understand the machining process in detail. Several phase-measurement techniques can be used in optical profilometry to characterize an object surface. The basic advantage of Mirau interferometry over other profile measurement techniques is that, interference fringes are formed only when the reference and the measurement paths are almost equal and this reduces the ambiguity in object positioning. In this paper, a novel optical layout with the Mirau configuration and applicable with polarization optics is adapted to measure microfeatures. Experiments were carried out with this setup on wafer surface with microfeatures, and the results were compared with that of a commercial surface profiler to demonstrate the applicability of the principle.