文档介绍：H174 Journal of The Electrochemical Society, 158 ͑2͒ H174-H177 ͑2011͒
0013-4651/2011/158͑2͒/H174/4/$ © The Electrochemical Society
Competition of Electromigration Reliability in Copper and
Nickel-Silicide
Yi-Lung Cheng,*,z Ming-Kai Shiau, Wei-Yuan Chung, and Ying-Lang Wang
Department of Electrical Engineering, National Chi-Nan University, Nan-Tou, Taiwan 54561
In this study, electromigration ͑EM͒ characteristics of Cu line and nickel ͑Ni͒–silicide on Cu-line/W-via/Ni–silicide structure were
compared. The experimental results revealed that petition of Cu line depletion and Ni–silicide migration depends on the
length of Cu line and the stress current density. For a longer Cu line or stress at a higher current density, the failure time of Cu-line
depletion is lower than that of Ni–silicide migration because the failure mode is Cu-line depletion. On the other hand, as the length
of Cu line is decreased and stressed at a lower current density, the failure mode is transferred to Ni–silicide migration due to a
͑͒͑͒
stronger back-stress effect in a shorter Cu line. The critical current densities jc , activation energy Ea , and current density
exponent ͑n͒ values for Cu-line depletion mode and Ni–silicide migration modes were characterized, which are used to predict the
EM lifetime at normal operation conditions. The results indicated that although the f