Microsc. Microanal. Microstruct.
Volume 4, Number 2-3, April / June 1993
|Page(s)||239 - 247|
Observation of Al-lines in LSI devices by ultra-high voltage electron microscopeAkio Takaoka, Noriyuki Okaya et Katsumi Ura
Department of Electronic Engineering, Faculty of Engineering, Osaka University, Yamada-oka 2-1, Suita, Osaka, 565, Japan
To clarify the mechanism caused by multi-layer effect, the ultra-HVEM at 2MeV is powerful because it has an excellent penetration power for specimens. By thinning the Si-substrate of LSI devices, we can carry out in-situ observations of phenomena arising in the process layers; in particular, we can observe the specimens without removing the passivation layers that strongly affect the generation of these phenomena. We show how the orientation of Al-lines depends on the step of process and how it relates to the incidence of stressmigration voids. From in-situ observation of electromigration in Al-lines with bamboo structure, it is seen that the main route of electromigration is the interface between the line and the passivation layer, and the migration is enhanced when a small gap exits in the interface.
0778 - Electron, positron, and ion microscopes; electron diffractometers.
8540 - Microelectronics: LSI, VLSI, ULSI; integrated circuit fabrication technology.
LSI circuit -- Multilayers -- High-voltage electron microscopy -- In situ -- Electromigration -- Grain orientation -- Atom migration -- Aluminium
© EDP Sciences 1993