X-ray photoemission spectroscopy (XPS), low-energy electron diffraction (LEED), reflection-absorption infrared spectroscopy (RAIRS), and scanning tunneling microscopy (STM) have been used to characterize the discontinuous oxide films formed following exposure of gaseous H8Si8O12 hydridosilsesquioxane clusters to Si(111)-7 x 7. Collectively, the four surface characterization techniques support a reaction involving cluster decomposition on the Si(111)-7 x 7 surface. The decomposition of H8Si8O12 upon reaction with S(111)-7 x 7 is in stark contrast with that of the reaction of H8Si8O12 with Si(100)-2 x 1 in which the cluster cage remains intact.