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Three‐dimensional microanalysis of the wire–pad contact region of integrated circuits
Author(s) -
Wu H.,
Takanashi K.,
Ono N.,
Cheng Zh. H.,
Sakamoto T.,
Sakou T.,
Owari M.,
Nihei Y.
Publication year - 2000
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/1096-9918(200008)29:8<508::aid-sia894>3.0.co;2-i
Subject(s) - materials science , microanalysis , cross section (physics) , secondary ion mass spectrometry , focused ion beam , mass spectrometry , ion , optics , analytical chemistry (journal) , chemistry , physics , organic chemistry , quantum mechanics , chromatography
We have developed a three‐dimensional microanalyser by combination of a gallium focused ion beam (Ga‐FIB), a secondary electron detector and a time‐of‐flight (ToF) mass spectrometer. The Ga‐FIB can create successive flat cross‐sections parallel to the interface. We performed ToF‐SIMS mapping by switching the d.c. mode of the Ga‐FIB in the cross‐sectioning to pulse mode after turning the cross‐section through 90°. Combination of these ToF maps on each cross‐section yields detailed three‐dimensional information from the interface region. The Au wire bonding interface after heat treatment was analysed. Analysis of the three‐dimensional elemental distribution in the contact region of the Au wire and Al pad was realized. An Au– Al alloy was found in the deep section of the contact interface, Al was distributed in the outer part as a ring and the center part was enclosed by Au. The deduced structure of the contact region of the Au wire and Al pad was discussed. Copyright © 2000 John Wiley & Sons, Ltd.