Ta/SiCN bilayer barrier for Cu–ultra low k integration

This paper reports the effect of a SiCN/Ta bilayer barrier on the electrical properties and thermal stability of single damascene lines for Cu-ultra low k integration. By introducing an additional SiCN layer prior to a Ta barrier, breakdown voltage, line-to-line leakage current and thermal stability could be significantly improved. The increase in the line resistance could be minimized by optimizing the thickness of SiCN layer in the multilayer lines.