The proposed slurry can be used to planarize polymeric candidate ILD materials such Benzocylobutene (BCB), SILK, Polyimide, etc. The slurry consists of colloidal suspension of nanoparticle abrasives made up of Tetraethylorthosilicate (TEOS)-derived silica and Zirconium-dioxide (ZrO2), its derivatives and any materials modified from ZrO2 and/or TEOS, in a chemically active medium. The base solution of the slurry consists of deionized (Dl) water, buffering agents like inorganic buffer comprised of inorganic acids such as TRIS-Hcl, its derivatives and variants, cleansing agents, surface modified catalysts, and surface reagents. The organic solvents like isopropyl alcohol, methanol, and other organic alcohols ranging from 0.0005 to 0.05% are employed for active dissolution of the chemical surface complex formed as a result of the slurry chemical action. The inorganic buffer is so chosen that the complex salts resulting from the reaction impart hydrophobicity to the polished thin film surface. The advantages of hydrophobicity include: a) reduced particle adhesion on surface, b) less intensive post-CMP clean, c) no surface degradation or contamination, etc.
Zantye, Parshuram B.; Kumar, Arun; and Kumar, Ashok, "CMP slurry for polymeric interlayer dielectric planarization" (2011). USF Patents. 393.
University of South Florida