Eco-friendly Corrosion Inhibitors for Multilevel Metal Interconnects of Integrated Circuits

The semiconductor industry is reaching new levels of sophistication because of the rapid development of integrated circuits (IC). There is a demand for electronic devices with high accuracy, low energy consumption, and high storage capacity. Copper, the traditional interconnecting metal material, is widely applied in large integrated circuits. Metal cobalt (Co) is regarded as a promising interconnection material alternative, because of its low electromigration, excellent stability, and high step coverage in the new technology nodes below 10 nm. Chemical mechanical planarization (CMP) is an important process for integrated circuit fabrication. It is necessary to introduce corrosion inhibitors to the slurry, to improve the surface flatness of the metal wafer, reduce the corrosion defects on the surface of the wiring metal, and restrain galvanic corrosion reaction of the wiring metal and barrier metal. However, cleaning residual wafer surface inhibitors after CMP is an equally important challenge. The selection of inhibitors, the adsorption mechanism of inhibitors, the synergistic effect between inhibitors and other reactants, and the desorption and desorption mechanism of inhibitors on metal surfaces in CMP postcleaning technology have been widely studied. In this chapter, the inhibitors used in CMP process of copper, cobalt, and their barrier metals, as well as corrosion inhibitor removal post CMP cleaning, are reviewed.