A Neutron Reflectivity Study of Silicon Oxide Thin Films

摘要

Neutron reflectivity was applied to the study of ultra-thin silicon oxide films, under investigation due to the demand for reduced dimensions of the elemental components in microelectronic devices. Silicon oxides were prepared through three different ways: chemical, electrochemical and thermal oxidation. From neutron reflectivity it was possible to obtain the oxide thickness, the Si/SiO_2 interface roughness, and the density of the layers. Impedance spectroscopy was also performed before and after the growth of an anodic oxide, in order to characterize the electrical behaviour of the interface. In complementary measurements, the chemical and thermal surface layers chemistry was obtained by infra-red spectroscopy. The anodic oxides found to be as dense as thermal oxides, with the chemical one, the less dense. This result was checked by FTIR.