TY - JOUR
T1 - Degradation of electromigration lifetime of Cu/Low-k interconnects by postannealing
AU - Kakuhara, Yumi
AU - Ueno, Kazuyoshi
PY - 2009/4/1
Y1 - 2009/4/1
N2 - The total thermal budget of the wafer fabrication process for structures with multilevel Cu/low-k interconnects has been increasing, and itseffect on the electromigration (EM) reliability of the lower-level interconnects has become a concern. The annealing of packaged samples including two-level interconnects for EM tests was shown here to be an effective method of evaluating the effect of the thermal budget on interconnects. EM lifetime was reduced by postannealing at the maximum process temperature (350 °C), and its failure mode was a slitlike void generated at the interface between the via and the Cu line. It was shown that the degradation mechanism was related to the contact between the via and the Cu line and that postannealing may affect the stress at this contact by changing the stress in the dielectric interlayer film.
AB - The total thermal budget of the wafer fabrication process for structures with multilevel Cu/low-k interconnects has been increasing, and itseffect on the electromigration (EM) reliability of the lower-level interconnects has become a concern. The annealing of packaged samples including two-level interconnects for EM tests was shown here to be an effective method of evaluating the effect of the thermal budget on interconnects. EM lifetime was reduced by postannealing at the maximum process temperature (350 °C), and its failure mode was a slitlike void generated at the interface between the via and the Cu line. It was shown that the degradation mechanism was related to the contact between the via and the Cu line and that postannealing may affect the stress at this contact by changing the stress in the dielectric interlayer film.
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U2 - 10.1143/JJAP.48.046507
DO - 10.1143/JJAP.48.046507
M3 - Article
AN - SCOPUS:67849124226
VL - 48
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 4
M1 - 046507
ER -