Surfactant slurry additives to improve erosion, dishing, and defects during chemical mechanical polishing of copper damascene with low K dielectrics

摘要

Slurries and methods for the chemical mechanical polishing of high density copper interconnects in a low k ILD are presented. In a particular embodiment of the present invention, a slurry for polishing copper is formed by combining a surfactant comprising an alkyl ethoxy organic acid such as glycolic acid ethoxylate lauryl ether (GAELE), an abrasive such as silica, an oxidizing agent such as hydrogen peroxide, and a chelating buffer system such as citric acid and potassium citrate dissolved in the mixture. This slurry provides a very low incidence of bent line defects, a low erosion rate, and a low dishing rate on a substrate comprising high density copper interconnects in a low k ILD. Embodiments of methods of the present invention use the disclosed slurries.