SPECTROSCOPIC ELLIPSOMETRY STUDY ON E-2 PEAK SPLITTING OF SI-GE SHORT-PERIOD SUPERLATTICES

We report spectroscopic ellipsometry (SE) studies on (Si)(2)(Ge)(12), (Si)(6)(Ge)(2), and (Si)(12)(Ge)(2) short period superlattices (SLs) w hose optical response has not been reported yet. Multilayer calculatio ns enabled us to determine the dielectric response of the superlattice layers. We report the clear observation of splitting of the E-2 peak in (Si)(m)(Ge)(n) superlattices contrary to the previous SE report tha t the separation was observed only in larger period SLs. (C) 1997 Amer ican Institute of Physics.