Title :
Via hole-related simultaneous stress-induced extrusion and void formation in Al interconnects
Author :
Shibata, Hajime ; Matsuno, T. ; Hashimoto, K.
Author_Institution :
Toshiba Corp., Kawasaki, Japan
Abstract :
A reliability issue caused by high temperature annealing after via hole opening is investigated. A high temperature anneal above 450 degrees C causes simultaneous Al extrusion at the via hole interface and void formation in Al interconnects, drastically degrading the reliability of Al lines with vias. Based on in situ observation of extrusion/void formation and two-dimensional elastic deformation analysis, it was found that this phenomenon is due to the movement of Al atoms towards the via hole interface resulting from the thermal expansion and the stress gradient formed in the Al line near the via hole during the anneal sequence. Experimental results and the influence of such an anneal process on the reliability of Al lines are discussed.<>
Keywords :
aluminium; annealing; circuit reliability; elastic deformation; metallisation; thermal expansion; 450 degC; Al extrusion; Al interconnects; high temperature annealing; reliability; stress gradient; stress-induced extrusion; thermal expansion; two-dimensional elastic deformation analysis; via hole interface; via hole opening; void formation; Impurities; Plasma applications; Plasma temperature; Plugs; Rapid thermal annealing; Surface topography; Surface treatment; Thermal stresses; Tin; Ultra large scale integration;
Conference_Titel :
Reliability Physics Symposium, 1993. 31st Annual Proceedings., International
Conference_Location :
Atlanta, GA, USA
Print_ISBN :
0-7803-0782-8
DOI :
10.1109/RELPHY.1993.283278
