Cure of Hydrogen Silsesquioxane for Intermetal Dielectric Applications

Abstract

AbstractCure is a significant process during back end of the line fabrication of integrated circuits with hydrogen silsesquioxane since it affects structure and properties of the spin on dielectric material. Reported herein is the effect of soak temperature, time, and oxygen concentration process parameters on structure and properties of hydrogen silsesquioxane. Results of the study emphasize the importance of an inert environment during the baseline recommended cure conditions of 400 °C for one hour in order to avoid oxidation and formation of polar silanol or water species. A 350 °C cure temperature is more robust to oxidation providing similar or improved properties. Shorter cure times result in similar structure and properties as the baseline cure which suggests that lower temperature and/or shorter cure time may provide value worth investigating by integrated circuit manufacturers.