Abstract
We report the use of non-contact optical interferometric microscopy (OIM) for surface topographic profiling. A Linnik optical configuration is used to create interferograms of an object surface. When the coherence condition between the two beams is met the phase information of the object surface can be extracted to establish its topographic contour image. Using a four-image phase-shifted algorithm with the synchronization of a piezoelectric actuator reference mirror positioning, the present single camera OIM can reconstruct a surface topography with a field of view of 312 μm × 234 μm, axial resolution of 3.31 nm, and lateral resolution of 488 nm, and an estimated maximum topography depth of 270 nm.
