Abstract

X-ray scattering from multilayers (such as Mo-Si) is to a large extent controlled by interface quality, which in turn is frequently controlled by surface morphology. Here we present a study of interface and surface morphology in both crystalline and amorphous Si layers deposited by evaporation in UHV at low substrate temperatures. For simplicity, the interfaces investigated are single monolayers of Ge, so that chemical effects are avoided. Amorphous Si films undergo morphological roughening and void formation, leading to apparent Si-Ge interface widths ≈5nm. In crystalline Si grown at the same temperature and deposition rate the roughness is considerably less marked, although localised void formation still occurs. Both the void density and the apparent interface width of single monolayers of Ge appears under these conditions to be linked to the thickness of crystalline Si deposited.

© 1992 Optical Society of America