Comparative Study of Hydrido Organo Siloxane Polymer and Hydrogen Silsesquioxane

Abstract

Low- k candidate spin-on-glass (SOG) material hydrido organo siloxane polymer (HOSP) was evaluated and compared with flowable oxide (FO x ). In particular, the chemical nature of the film and the effects of various processing steps on this chemical nature were investigated using Fourier transform infrared spectroscopy (FTIR), thermal desorption spectroscopy (TDS), a C – V meter and a stress gauge. The water absorption after various post-etch treatments 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 FO x and is more immune against moisture uptake. However, HOSP becomes more vulnerable to moisture absorption after oxygen plasma treatment. Electrical data from the process integration of HOSP were compared to those of FO x and conventional plasma-deposited oxide. The via resistance using HOSP was higher than that using the other materials. In particular, HOSP samples exhibited strong dependence on misalignment in resistance or leakage current measurements. The scanning electron microscope (SEM) image of these samples show that the electrical properties of HOSP samples resulted from a decrease in the actual via metal cross-section area due to via-poisoning.