Advanced metal barrier free Cu damascene interconnects with PECVD silicon carbide barriers for 90/65-nm BEOL technology

Abstract

Advanced metal barrier free (MBF) Cu dual damascene interconnects (DDIs) have been successfully fabricated using a low-k CVD OSG (k=2.5) and PECVD silicon carbides for the first time. With PECVD silicon carbides replacing TaN, the Cu DDIs thus built showed 8% better in interconnect RC delay, 36% lower in via resistance and three orders of magnitude lower in line-line leakage at 200/spl deg/C. The newly developed technology also enhanced Cu TDDB lifetime by more than three orders of magnitude. On the MBF DDIs, 15%-faster 90-nm CMOS device operation has been achieved, which makes the newly developed MBF Cu DDI technology promising for high performance sub-90 nm CMOS devices and beyond.