Quantitative analysis of correlation between insulator surface copper contamination and TDDB lifetime based on actual measurement

We have analyzed the correlation between insulator surface copper contamination and time-dependent dielectric breakdown (TDDB) quantitatively for the first time. TDDB lifetime strongly depends on the copper contamination after CMP process, and it is important to control the redox potential to be less than -0.5 V vs. NHE and to utilize a chelating agent on cleaning sequence. Furthermore, we have successfully optimized the post-CMP sequence to decrease the size of antioxidant-copper complex, and improved the TDDB lifetime.