TDDB reliability improvement in Cu damascene by using a bilayer-structured PECVD SiC dielectric barrier

C.C. Chiang, M.C. Chen, Z.C. Wu, L.J. Li, S.M. Jang, C.H. Yu, M.S. Liang
Proceedings of the IEEE 2002 International Interconnect Technology Conference (Cat. No.02EX519)  
This work investigates the thermal stability and barrier characteristics of two species of silicon carbide dielectric films, a-SiCN with a dielectric constant of 4.9 and a-Sic with a dielectric constant of 3.8. The TDDB lifetime of Cu damascene metallization structure is greatly improved by using a a-SiCNI a-SIC bilayer dielectric stack as the etching stop layer (ESL). This improvement is presumably due to the a -S i c dielectric's lower leakage current, absence of nitridation on Cu surface,
more » ... better adhesion on Cu as well as OSG intermetal dielectric (IMD), though the a -S i c film has a very slow deposition rate. We believe that the a-SiCNIa-Sic bilayer dielectric is a favorable combination for the ESL because a-SiCN can protect a-Sic from plasma attack during the photoresist stripping.
doi:10.1109/iitc.2002.1014933 fatcat:doev4h6kdzdihg33gvsbhymo3e