My presentation at the IEEE - Internationa Reliability Physics Symposium 2007

1. MODELING OF INTERCONNECT DIELECTRIC LIFETIME UNDER STRESS CONDITIONS AND NEW EXTRAPOLATION METHODOLOGIES FOR TIME-DEPENDENT DIELECTRIC BREAKDOWN Gaddi S. Haase , Joe W. McPherson Texas Instruments, Dallas, TX, USA 4E.2

7. The actual line-to-line spacing distribution in a 65nm technology comb-comb test structure The observed spacing distributions, from many cross-sectional electron micrographs for each test structure, were fitted with asymmetric normal distributions (solid curves) for ease of use in the simulation. M1 M2 M1

11. Simulated apparent TDDB Using DUTs from three spacing-distribution zones. However, the “true”  used in this simulation was 2.0 The “apparent”  is only ~1 Simulated data Note: The true  is dictated by the actual material variation

12. At low voltage,  appears again as 2.0 Extending the simulation to operating voltage : Simulated data At operating voltages, the spacing variations do not affect the lifetime uncertainty as much as at test voltages ! The “true”  value can be used for product reliability assessment

16. Evaluating the true  with V-ramp tests Simulated data Simulated data Using V-ramp to breakdown at two ramp rates , s i /  can be extracted at F =63%, and used to derive  from V bd,63% vs. area curves.