Investigations Of The Chemical-Mechanical Polishing Of Polymer Films For ILD Applications

Abstract

AbstractLow dielectric constant films are being investigated as the interlayer dielectric (ILD) in a multilevel interconnection scheme for advanced ULSI circuits. In such applications they will be subjected to planarization processes using chemical-mechanical polishing (CMP), either directly during dielectric planarization or indirectly in the final stages of metal patterning using the Damascene process. In this paper we report the results of our initial investigations of the CMP of three different polymers, all with dielectric constant in the range of 2.3 – 2.7 and with different mechanical and chemical properties. The CMP was carried out using alumina as the abrasive in basic and acidic pH slurries. The effect of preannealing the polymer on the CMP behavior was also investigated