Method to Determine the Root Cause of Low- $\kappa$ SiCOH Dielectric Failure Distributions

Low- $\kappa $ SiCOH reliability is a growing concern for integrated circuit reliability. An important consideration for product qualification involves the accurate extrapolation to the low percentile failures based on the results from a group of samples. A method is presented to determine the root cause of failure distributions amongst a group of dielectric samples using voltage ramp data. Samples’ leakage current traces and breakdown voltages are compared with each other. Using this method, it was determined that the dielectric spacing variation dominates across-wafer failure, while variation of local breakdown strength affects in-chip failure.