Tushar Mandrekar

Barrier Integrity Effect on Leakage Mechanism and Dielectric Reliability of Copper/OSG Interconnects

In this paper, we investigate the effect of copper diffusion barrier integrity on the leakage behavior and dielectric reliability of copper/micro porous organo-silica-glass (OSG) interconnects. Significant differences in the field dependence of TDDB median-time-to-failure are observed when comparing sub-critical and sealing barriers. Also for the temperature acceleration of TDDB, a significant difference is found which is reflected in the thermal activation energies. With fast voltage ramp measurements, I-V curves of samples with subcritical and sealing barriers are compared before and after constant current stresses. Above 1.4 MV/cm, the dominant leakage mechanism is found to be Frenkel-Poole emission regardless of barrier treatments and stress times. Below 1.4 MV/cm, however, the I-V characteristic is modulated by the barrier integrity, which can be attributed to copper diffusion into the intermetal dielectric.

Ultrathin integrated ion metal plasma titanium and metallorganic titanium nitride liners for sub 0.18 μm W based metallization schemes for >500 MHz microprocessors

This study will specifically address the results of integrating IMP Ti and MOCVD TiN on a high vacuum system. Results of design of experiments used for process characterization and optimizing device parametric such as contact and via resistance will be discussed, in particular with respect to unlanded via schemes. Finally, Cost of Ownership calculations will be presented in comparison to conventional PVD technologies. In summary, the integration of IMP Ti and MOCVD TiN enables the deposition of a highly cost effective, low resistivity, ultra-thin, and low- temperature liners for sub 0.18 micrometers technology node thereby enabling > 500 MHz microprocessor technology.