APPLICATION OF INFRARED FOURIER-TRANSFORM PHASE-MODULATED ELLIPSOMETRY TO THE CHARACTERIZATION OF SILICON-BASED AMORPHOUS THIN-FILMS

Multilayers of silicon-based amorphous thin films were characterized t o test the performance of Fourier transform phase-modulated ellipsomet ry (FTPME) in absolute measurements (thickness and refractive index). The multilayers consist of a stack of silicon dioxide (SiO2), hydrogen ated amorphous silicon (a-Si:H) and NiCr thin films on c-Si substrates . Results provided by FTPME are compared with those from UV-visible ph ase-modulated ellipsometry and transmission electron microscopy. The t hicknesses of the layers determined by the three techniques agrees wit hin 3%. Similar volume void fractions of approximately 8% for the sili con dioxide layers are found by UV-visible and IR ellipsometry. (C) 19 98 Elsevier Science S.A.