Advanced bilayer low-k dielectric cap for reliable high performance Cu-low k interconnects

Abstract

This paper presents the performance of a low k advanced dielectric Cu barrier (k ≤ 4.0) for 45 nm CMOS devices and beyond while still maintaining equivalent reliability as compared to traditional (k=5.3) SiCNx cap materials. This new PECVD SiCNx/SiCNy bilayer film was developed with varying composition to achieve: 1) a high nitrogen content SiCNx bottom layer with robust mechanical properties, good barrier properties, and excellent interfacial characteristics with Cu. 2) a lower nitrogen content SiCNy top layer with lower dielectric constant, and good plasma RIE selectivity. This paper will discuss the integration and reliability results of this advanced low-k Cu barrier for use in advanced CMOS devices. © 2009 Materials Research Society.