Development of Innovative Tunable Polishing Formulations for Chemical Mechanical Planarization of Silicon Nitride, Silicon Carbide, and Silicon Oxide

This study focuses on the development of innovative formulations for silicon carbide and silicon nitride polishing with tuneable removal rates and selectivity with respect to silicon oxide dielectric films. The approach involves a unique combination of chemical and mechanical action to polish the inherently hard and chemically inert silicon carbide and silicon nitride films. It is hypothesized that chemical additives activate and soften the silicon carbide and/or silicon nitride film surfaces, requiring only minimal abrasive action to remove the softened layers, while keeping the silicon oxide removal rates low. Insight into type of functional groups responsible for selective removal of silicon carbide and silicon nitride films is gained. The effects of the functional group and the backbone structure of the chemical additives are illustrated with several examples. Keywords: Silicon Nitride, Silicon Carbide, Planarization, Chemical Mechanical Polishing, Chemical Additives, Slurry