{'fraction_non_alphanumeric': 0.033873343151693665, 'fraction_numerical': 0.0014727540500736377, 'mean_word_length': 4.686192468619247, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Competition of Electromigration Reliability in Copper and Nickel-Silicide

In this study, electromigration (EM) characteristics of Cu line and nickel (Ni)-silicide on Cu-line/W-via/Ni-silicide structure were compared. The experimental results revealed that EM competition 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 (j c ), activation energy (E a ), and current density exponent (n) 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 failure time of Ni-silicide migration mode is lower than that of Cu-line depletion mode for a shorter Cu line at a higher stress temperature, Ni-silicide migration with a higher activation energy ( ~ 1.7 eV) results in a longer EM lifetime at a lower operation temperature.