There is an increasing reliability concern of thermal stress-induced and electromigration-induced failures in multilevel interconnections in recent years. This paper reports our investigations of thinfilm cracking of a multilevel interconnect due to fast temperature cycling and electromigration stresses. The fast temperature cycling tests have been performed in three temperature cycle ranges. The failure times aare represented well by a Weibull distribution. The distributions are relatively well behaved with generally similar slope (shape factor). The failure mechanism is well fitted by the Coffin-Manson equation indicating a uniform acceleration. The observation of cracking in the interlayre dielectric due to fast temperature cycling stress from failure analysis agrees well with the failure mechanism modeling and the calculated Coffin-Manson exponent. Electromigration experiments have shown that devices failed due to extrusion-shorts without increasing of resistance of metal line. The failure times are represented better by the Weibull distribution than by the lognormal distribution (normally used for electromigration data). A simulation of stress buil-up in metal line using an electromigration simulator confirmed that the cracking of interlayer dielectric is the weakest spot and most likely to cause electromigration failure.
Nguyen, V. H., Nguyen, H., Salm, C., Vroemen, J., Voets, J., Krabbenborg, B. H., ... Kuper, F. G. (2002). Fast temperature cycling and electromigration induced thin film cracking multilevel interconnection: experiments and modeling. Microelectronics reliability, 42(9-11), 1415-1420. [10.1016/S0026-2714(02)00161-0]. https://doi.org/10.1016/S0026-2714(02)00161-0