FULL-FIELD MAPPING OF THE STRESS-INDUCED BIREFRINGENCE ON THE INTERNAL INTERFACES USING A POLARIZED LOW COHERENCE LIGHT INTERFEENCE MICROSCOPE

摘要

In any semiconductor and optic materials such as ceramic/wafer/polymer/glass, changes in birefringence may, for instance, indicate changes in functionality, structure and stress inside the materials. These devices are usually fabricated by a sequence of planar process to form a multiple layer structure. Manufacturers need to detect and classify the internal interface adhesion properties between layers at many different stages in the construction of the devices. For the reason, we had developed a polarization-sensitive optical coherence microscope (PS-OCM) to inspect the variation of the birefringence of the internal interface of layer structures. The PS-OCM is an extended embodiment of the OCT technology that enables the polarization state of backscattered light to be detected and quantified. By simultaneous detection of interference fringes in two orthogonal polarization states allows determination of the Strokes parameters of light. Comparison of the Strokes parameters of the incident state to that reflected from the sample can yield a depth-resolved map of optical properties such as birefringence and refractive index.