Barrier Property of a Ta/MnSixOy Layer Formed by a Ta-Mn Alloy for a Cu Interconnect

The advanced back-end module of very-large-scale-integrated-circuits (VLSIs) requires an ultrathin diffusion barrier layer between the Cu interconnect and low-K oxides. In this letter, we investigated the electrical properties of the barrier layer formed by a Ta-Mn alloy on SiO 2 . A diffusion barri...

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Bibliographic Details
Published inIEEE electron device letters Vol. 37; no. 8; pp. 1048 - 1050
Main Authors Cheng-Lun Hsin, Kun-Yen Lin
Format Journal Article
LanguageEnglish
Published IEEE 01.08.2016
Subjects
Annealing
Cu interconnect
Current density
diffusion barrier
Electromigration
Metals
Reliability
Resistance
TaMn
Temperature measurement
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Summary:The advanced back-end module of very-large-scale-integrated-circuits (VLSIs) requires an ultrathin diffusion barrier layer between the Cu interconnect and low-K oxides. In this letter, we investigated the electrical properties of the barrier layer formed by a Ta-Mn alloy on SiO 2 . A diffusion barrier layer self-formed at the interface during annealing, and the Ta/MnSi x O y bilayer structures were investigated by standard microscopy. Black's equation and the measured mean-time-to-failure (MTTF) were used to obtain the reliability characteristics under different temperatures and current densities. The reliability is approximately two times better than that of the conventional TaN/Ta counterpart. The confidence intervals at 95% for each MTTF confirmed the single failure mode, and the electromigration phenomenon was observed to be the failure mechanism. Our results provide evidence that Ta/MnSi x O y is a promising barrier material for Cu interconnects in VLSIs.
ISSN:0741-3106
1558-0563
DOI:10.1109/LED.2016.2582499