This study investigates the thermal stability of thermally grown silicon dioxide (thermal SiO(2)) fluorinated silicate glass (FSG), hydrogen silsesquioxane (HSQ), and organosilicate glass (OSG). Samples with and without sputtered copper films, as-prepared and after annealing at 200 similar to 800 degrees C in vacuum, have been investigated by various methods of analysis. For the as-prepared dielectrics, it is found that the densities of HSQ and OSG are less than those of SiO(2) and FSG due to the greater roughness and more porous structure of HSQ and OSG. After annealing at 800 degrees C, the HSQ structure converts to a SiO(2)-like structure, which is mainly due to decomposition of HSQ. Furthermore, the methyl groups and oxygen atoms are also liberated from OSG after high temperature annealing. A plateau in the Cu profile near the Cu/dielectric interface is observed in the results of secondary ion mass spectrometry after annealing at 450 degrees C. On the other hand, penetration of Cu atoms across the interface between Cu and HSQ, and across the interface between Cu and OSQ, are observed for Cu/HSQ and Cu/OSG systems after annealing at 450 degrees C. The thermal stability of these four dielectrics are discussed and compared. (c) 2007 Elsevier B.V. All rights reserved.