TiN and TaN diffusion barriers in copper interconnect technology: Towards a consistent testing methodology

The present status of work on diffusion barriers for copper in multilevel i nterconnects is surveyed briefly, with particular emphasis on TIN and TaN, and silicon dioxide as the interlayer dielectric. New results are presented for these materials, combining thermal annealing and bias temperature stre ss testing. With both stress methods, various testing conditions are compar ed using capacitance-vs-voltage (C-V) and leakage current-vs-voltage (I-V) measurements to characterize the stressed samples. From an evaluation of th ese data and a comparison with other testing approaches, conditions for a c onsistent testing methodology of barrier reliability are outlined.