In situ study of void growth kinetics in electroplated Cu lines
Authors:
- 15 August 2002
- journal article
- research article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 92 (4) , 1803-1810
Abstract
An in situ electromigration apparatus was used to study the kinetics of void growth in unpassivated, electropolated copper damascene lines. Voids were observed to grow by consuming grains in a stepwise fashion, either by grain thinning or by an edge displacement mechanism. Surface diffusion was found to be the primary diffusion path for void growth. In addition, grain boundaries provided a secondary path for copper diffusion in polycrystalline structures and nucleation sites for void growth in bamboo structures. Void growth rate was measured as a function of sample temperature and linewidth using a scanning electron microscope. An electromigration activation energy of 0.9±0.1 eV was determined for the copper voiding process. The effect of linewidth on void growth rate was also investigated and found to be negligible, consistent with a surface-diffusion dominated model for void growth. The in situ apparatus also made it possible to directly correlate changes in electrical resistance with physical changes taking place in the test structures.Keywords
This publication has 26 references indexed in Scilit:
- Relationship between microstructure and electromigration damage in unpassivated PVD copper damascene interconnectsMicroelectronics Reliability, 2000
- Electromigration damage in mechanically deformed Al conductor lines: dislocations as fast diffusion pathsActa Materialia, 2000
- Dynamics of electromigration induced void/hillock growth and precipitation/dissolution of addition elements studied by in-situ scanning electron microscopy resistance measurementsMicroelectronics Reliability, 1999
- Electromigration proximity effects of two neighboring fast-diffusion segments in single-crystal aluminum linesJournal of Applied Physics, 1999
- In-Situ Electromigration Damage of Al Interconnect Lines and the Influence of Grain OrientationMRS Proceedings, 1999
- In situ electromigration damage in Al interconnect lines in the SEM and the influence of grain orientationAIP Conference Proceedings, 1999
- In-situ study of interconnect failures by electromigration inside a scanning electron microscopeAIP Conference Proceedings, 1999
- Transmission electron microscopy of AlCu interconnects during in-situ electromigration testingThin Solid Films, 1997
- In situ scanning electron microscope comparison studies on electromigration of Cu and Cu(Sn) alloys for advanced chip interconnectsJournal of Applied Physics, 1995
- In-Situ Electromigration Stressing in Transmission Electron Microscopy for Al-Cu InterconnectsMRS Proceedings, 1994