Study on Interface Analysis by Using Spectroscopic Ellipsometry

Spectroscopic ellipsometry (SE) has been proved to be a powerful nondestructive method for analyzing multilayer structures. Recently, a new interface model, which utilizes a parametric model to describe the alloy dielectric function of an arbitrary alloy composition, was introduced. Even though the new model could reconstruct the experimental spectrum precisely, the resulting thickness value for each composite layer in the graded interface layers seemed to be unreasonably asymmetric. To check the validity of the new model, we performed z-contrast scanning transmission electron microscopy (STEM) and compared the result with those from SE, confirming that the SE analysis can be considered to be reliable.