標題: Effect of the tantalum barrier layer on the electromigration and stress migration resistance of physical-vapor-deposited copper interconnect
作者: Chin, YL
Chiou, BS
Wu, WF
電子工程學系及電子研究所
Department of Electronics Engineering and Institute of Electronics
關鍵字: Cu films;barrier layer;microstructure;reliability;interconnect;electromigration;Ta/Cu/Ta multilayer
公開日期: 1-五月-2002
摘要: The effects of a Ta barrier layer on electromigration and stress migration of Cu films are investigated. The Ta barrier layer enhances both the (111) texture and the median grain size of the annealed Cu films. At 225degreesC, the electromigration mean time to failure (225degreesC-MTF) of Ta/Cu/Ta multilayer interconnects is about two times longer than that of Cu monolayer interconnects. After 500 thermal cycles, the 225degreesC-MTF of Ta/Cu/Ta multilayer interconnects does not change and is about three times longer than that of Cu monolayer interconnects. The activation energy E-a of electromigration of Ta/Cu/Ta multilayer interconnects is 0.77 eV, which is higher than that of Cu monolayer interconnects (0.65 eV). Since the Ta/Cu/Ta specimen has enhanced crystallographic texture and larger grain size. it has both higher electromigration endurance and thermal stress resistance than Cu. However. the measured MTF is shorter than that predicted by an equation proposed by Vaidya and Sinha [Thin Solid Films 75 (1981) 253]. The shorter MTF and smaller E-a values for the Ta/Cu/Ta multilayer compared to the predicted ones are due to the weak Ta/Cu interface, A lifetime of 100 years is predicted for Ta/Cu/Ta multilayer interconnects with and without 500 thermal cycle stress.
URI: http://dx.doi.org/10.1143/JJAP.41.3057
http://hdl.handle.net/11536/28810
ISSN: 0021-4922
DOI: 10.1143/JJAP.41.3057
期刊: JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS
Volume: 41
Issue: 5A
起始頁: 3057
結束頁: 3064
顯示於類別:期刊論文


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  1. 000176515700057.pdf