Comparative study of hydride organo siloxane polymer and hydrogen silsesquioxane

Low-k candidate spin-on-glass (SOG) material hydride organo siloxane polyme r (HOSP) was evaluated and compared with flowable oxide (FOx). In particula r, the chemical nature of the film and the effects of various processing st eps' on this chemical nature were investigated using Fourier transform infr ared spectroscopy (FTIR), thermal desorption spectroscopy (TDS), a C-V mete r and a stress gauge. The water absorption after various post-etch treatmen ts was found to be a crucial factor affecting the dielectric properties of the film. HOSP proved to be a dielectric material with a lower k value than FOx and is more immune against moisture uptake. However, HOSP becomes more vulnerable to moisture absorption after oxygen plasma treatment. Electrica l data from the process integration of HOSP were compared to those of FOx a nd conventional plasma-deposited oxide. The via resistance using HOSP was h igher than that using the other materials. In particular, HOSP samples exhi bited strong dependence on misalignment in resistance or leakage current me asurements. The scanning electron microscope (SEM) image of these samples s how that the electrical properties of HOSP samples resulted from a decrease in the actual via metal cross-section area due to via-poisoning.