TITLE

Study of Electromigration Induced Void Nucleation, Growth, and Movement in Cu Interconnects

AUTHOR(S)

Vairagar, A. V.; Mhaisalkar, S. G.; Krishnamoorthy, A.; Tu, K. N.; Gusak, A. M.; Zaporozhets, T.; Meyer, M. A.; Zschech, E.

PUB. DATE

December 2004

SOURCE

AIP Conference Proceedings;2004, Vol. 741 Issue 1, p135

SOURCE TYPE

Academic Journal

DOC. TYPE

Article

ABSTRACT

Electromigration mechanism in dual-damascene Cu interconnects was studied using conventional package level accelerated tests and in-situ SEM characterization technique. Improvement in electromigration performance was observed for upper as well as lower layer via-fed structures when the Cu/dielectric cap interface was modified by various Cu surface treatments after chemical mechanical polishing. Electromigration mechanism consisting void movement along the Cu/dielectric cap interface and agglomeration at the cathode via was revealed during in-situ electromigration characterization. This mechanism is different from the current understanding of electromigration. Mechanisms of void trapping at grain boundaries and the radius dependence of void velocity were experimentally observed. Analytical models to elucidate these observations have been proposed. � 2004 American Institute of Physics

ACCESSION #

15696543

Tags: ELECTRODIFFUSION;  COPPER;  DIELECTRICS;  INTERFACE circuits;  AGGLOMERATION;  CATHODES

 

Related Articles

• In situ observation of electromigration-induced void migration in dual-damascene Cu interconnect structures. Vairagar, A. V.; Mhaisalkar, S. G.; Krishnamoorthy, Ahila; Tu, K.N.; Gusak, A. M.; Meyer, Moritz Andreas; Zschech, Ehrenfried // Applied Physics Letters;9/27/2004, Vol. 85 Issue 13, p2502 

  In situ electromigration experiments were carried out to study electromigration-induced failure in the upper and lower layers in dual-damascene Cu test structures. The observations revealed electromigration-induced void movement along the Cu/dielectric cap interface. It supports the premise that...

• Statistical Analysis of Electromigration in Cu Interconnects With Multi-link Test Structures. Justison, P.; Gall, M.; Thrasher, S.; Hauschildt, M.; Hernandez, R.; Capasso, C.; Kawasaki, H.; Ho, P. S. // AIP Conference Proceedings;2004, Vol. 741 Issue 1, p148 

  The continual downward scaling of devices and increases in drive current have required an ever shrinking interconnect pitch and higher current densities. In order to overcome both the higher signal delay, as well as reliability concerns, new metallization technologies like Cu interconnects and...

• Study of Electromigration-Induced Failures on Cu Pillar Bumps Joined to OSP and ENEPIG Substrates. Hsiao, Yu-Hsiang; Lin, Kwang-Lung; Lee, Chiu-Wen; Shao, Yu-Hsiu; Lai, Yi-Shao // Journal of Electronic Materials;Dec2012, Vol. 41 Issue 12, p3368 

  This work studies electromigration (EM)-induced failures on Cu pillar bumps joined to organic solderability preservative (OSP) on Cu substrates (OSP-bumps) and electroless Ni(P)/electroless Pd/immersion Au (ENEPIG) under bump metallurgy (UBM) on Cu substrates (ENEPIG-bumps). Two failure modes...

• Statistical analysis of electromigration lifetimes and void evolution. Hauschildt, M.; Gall, M.; Thrasher, S.; Justison, P.; Hernandez, R.; Kawasaki, H.; Ho, P. S. // Journal of Applied Physics;2/15/2007, Vol. 101 Issue 4, p043523 

  Electromigration failure statistics and the origin of the log-normal standard deviation for copper interconnects were investigated by analyzing the statistics of electromigration lifetime and void size distributions at various stages during testing. Experiments were performed on 0.18 �m wide...

• The Hillock Formation in a Cu/Sn-9Zn/Cu Lamella upon Current Stressing. Shih-Ming Kuo; Kwang-Lung Lin // Journal of Electronic Materials;Oct2007, Vol. 36 Issue 10, p1378 

  The electromigration (EM) that occurs in a Cu/Sn-9Zn/Cu lamella was investigated for hillock formation at room temperature with a current density of 10� A/cm� for up to 230 h. Hillocks and cavities grew in the middle of the bulk solder and at the cathode, respectively. The formation of...

• Electromigration behavior of the Cu/Au/SnAgCu/Cu solder combination. Tsung-Chieh Chiu; Kwang-Lung Lin // Journal of Materials Research;Jan2008, Vol. 23 Issue 1, p10 

  The electromigration behavior of the Cu/Au/SnAgCu/Cu combination was investigated under 103 A/cm2 of current stressing at ambient temperature. The Au layer, when it acts as a cathode, was consumed continuously, and no significant compound was found at the interface. Meanwhile, Cu6Sn5 was formed...

• Microstructure Effect on Electromigration-Induced Degradation of Inlaid Copper Interconnects. Zschech, E.; Meyer, M. A.; Prinz, H.; Zienert, I.; Grafe, M.; Langer, E.; Geisler, H. // AIP Conference Proceedings;2004, Vol. 741 Issue 1, p196 

  Electromigration-induced degradation processes in via/line dual inlaid copper interconnect test structures are discussed based on experimental studies. Void formation, growth and movement, and consequently interconnect degradation, depend on both interface bonding and copper microstructure. Void...

• Reservoir effect and the role of low current density regions on electromigration lifetimes in copper interconnects. Gan, Z. H.; Shao, W.; Mhaisalkar, S. G.; Chen, Z.; Hongyu Li; Tu, K. N.; Gusak, A. M. // Journal of Materials Research;Sep2006, Vol. 21 Issue 9, p2241 

  Electromigration (EM) in copper dual-damascene interconnects with extensions(also described as overhang regions or reservoirs) in the upper metal (M2) were investigated. It was found that as the extension length increases from 0 to 60 nm, the median-time-to-failure increased from 50 to 140 h,...

• Impact of Low k Dielectrics on Electromigration Reliability for Cu Interconnects. Ho, Paul S.; Ki-Don Lee; Ogawa, Ennis T.; Yoon, Sean; Xia Lu, Sean // AIP Conference Proceedings;2003, Vol. 683 Issue 1, p533 

  Multi-link statistical test structures were used to study the effect of low k dielectrics on EM reliability of Cu interconnects. Experiments were performed on dual-damascene Cu interconnects integrated with oxide, CVD low k, porous MSQ, and organic polymer ILD. The EM activation energy for Cu...

Read the Article