Voltage Ramp and Time-Dependent Dielectric Breakdown in Ultra-Narrow Cu/SiO2 Interconnects

Voltage ramp dielectric breakdown (VRBD) and time-dependent dielectric breakdown (TDDB) characteristics of ~40nm-wide Cu/SiO
2
interconnect dielectrics were investigated. The addition of a SiH
4
treatment before capping SiN deposition led to more uniform breakdown fields, and better TDDB performance. The integration of a Ti-based barrier resulted in the best uniformity of breakdown fields, and a dramatic enhancement of TDDB reliability. The relationship between the VRBD and the TDDB characteristics was discussed, and the effect of SiH
4
treatment was analyzed using TEM.