Title :
Two electromigration failure modes in polycrystalline aluminum interconnects
Author :
Atakov, E.M. ; Clement, J.J. ; Miner, B.
Author_Institution :
Digital Equipment Corp., Hudson, MA, USA
Abstract :
Grain-boundary (GB) erosion-type voids and transgranular slit-like voids are found to be two competing electromigration (EM) failure modes in partly-bamboo interconnects. The effects of metal microstructure, passivation thickness, line width and length, and EM stress conditions on the two failure modes were studied. The kinetics for GB-type failures is strongly affected by the threshold effect in polycrystalline segments and is well described by the Multi-Lognormal (MLN) function with stress-dependent number of elements. The model predicts that the EM resistance of partly-bamboo lines at VLSI operating conditions is limited by the slit failure mode, rather than by GB-type failures.<>
Keywords :
VLSI; aluminium; circuit reliability; electromigration; failure analysis; grain boundaries; integrated circuit technology; metallisation; passivation; voids (solid); Al; EM stress conditions; VLSI operating conditions; electromigration failure modes; grain-boundary erosion-type voids; line length; line width; metal microstructure; multi-lognormal function; partly-bamboo interconnects; passivation thickness; polycrystalline interconnects; slit failure mode; threshold effect; transgranular slit-like voids; Aluminum; Electromigration; Grain size; Heating; Kinetic theory; Passivation; Stress; Temperature; Testing; Very large scale integration;
Conference_Titel :
Reliability Physics Symposium, 1994. 32nd Annual Proceedings., IEEE International
Conference_Location :
San Jose, CA, USA
Print_ISBN :
0-7803-1357-7
DOI :
10.1109/RELPHY.1994.307834
