Linear oligosilanes (R(SiR2)10R), permethyldecasilane (R = CH3), and perpropyldecasilane (R = C3H7), were
vacuum-deposited onto quartz substrates under various conditions. Molecular orientation in the deposited
thin films was investigated by X-ray diffractometry and absorption spectroscopy with a varying incident
angle to the substrate. Two types of highly ordered multilayered structures, one with molecular orientation
normal to the substrate and the other with oblique orientation, were observed in the permethyldecasilane thin
films deposited at room temperature. When deposited at −150 °C, on the other hand, the molecular orientation
was largely normal to the substrates but the multilayered structure was hardly formed. For perpropyldecasilane
thin films, an interdigitated structure with molecular orientation normal to the substrate was found when
deposited at and above room temperatures.