Size effect in a percolation model of interconnect failure

The problem of interconnect failure is studied in the framework of percolat ion theory. The probability failure of a long interconnect due to statistic al fluctuations of defects is found. It is demonstrated that two possible d iapasons of length to width ratios exist. For extremely long wires, the per colation threshold is determined by rare accumulation of defects, breaking down the wire. For moderately long wires, the threshold concentration of de fects is near the macroscopic percolation threshold. The lowering of thresh old due to finite width of wire is found. The percolation threshold is foun d in a two-dimensional system, containing the individual vacancies and void s, caused by coalescence of vacancies. (C) 2000 Elsevier Science B.V. All r ights reserved.