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Evaluation of TiW + Al/Cu electromigration performance
Author(s) -
Armstrong N. P.
Publication year - 1991
Publication title -
quality and reliability engineering international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 62
eISSN - 1099-1638
pISSN - 0748-8017
DOI - 10.1002/qre.4680070414
Subject(s) - electromigration , benchmark (surveying) , materials science , activation energy , metallurgy , analytical chemistry (journal) , chemistry , composite material , geology , geodesy , chromatography
Al/4 per cent Cu tracks with a TiW underlayer have been life‐tested for electromigration between 180° and 235°C, and activation energy for EM in the tracks has been obtained. Comparison with other life‐test data has shown that the previous omission of a vacuum break between TiW and Al/Cu depositions resulted in 10x improvement in t 50 . However, the present films remain greatly superior to Al/Cu alone: the improved slope implies a 10x increase in t 0.1% —an appropriate benchmark for circuit failure. Secondary ion mass spectrometry and X‐TEM have been used to investigate reasons for the large observed effect of vacuum break on EM life. Results lead to the suggested use of Al/Cu/Ti alloys in future.