The Effects of the Mechanical Properties of the Confinement Material on Electromigration in Metallic Interconnects
- 1 August 2000
- journal article
- Published by Springer Nature in Journal of Materials Research
- Vol. 15 (8) , 1797-1802
- https://doi.org/10.1557/jmr.2000.0259
Abstract
New low-dielectric-constant interlevel dielectrics are being investigated as alternatives to SiO2 for future integrated circuits. In general, these materials have very different mechanical properties from SiO2. In the standard model, electromigration-induced stress evolution caused by changes in the number of available lattice sites in interconnects is described by an effective elastic modulus, B. Finite element calculations were carried out to obtain B as a function of differences in the modulus, E, of interlevel dielectrics, for several stress-free homogeneous dilational strain configurations, for several line aspect ratios, and for different metallization schemes. In contradiction to earlier models, we found that for Cu-based metallization schemes with liners, a decrease in E by nearly two orders of magnitude has a relatively small effect on B, changing it by less than a factor of 2. However, B, and therefore the reliability of Cu interconnects, can be strongly dependent on the modulus and thickness of the liner material.Keywords
This publication has 13 references indexed in Scilit:
- CVD TaN barrier for copper metallization and DRAM bottom electrodePublished by Institute of Electrical and Electronics Engineers (IEEE) ,2003
- Scaling effect on electromigration in on-chip Cu wiringPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2003
- Full copper wiring in a sub-0.25 μm CMOS ULSI technologyPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- Electromigration path in Cu thin-film linesApplied Physics Letters, 1999
- Simulations of stress evolution and the current density scaling of electromigration-induced failure times in pure and alloyed interconnectsJournal of Applied Physics, 1999
- Stable state of interconnect under temperature change and electric currentActa Materialia, 1998
- Damascene copper interconnects with polymer ILDsThin Solid Films, 1997
- Effects of microstructure on interconnect and via reliability: Multimodal failure statisticsJournal of Electronic Materials, 1993
- Stress evolution due to electromigration in confined metal linesJournal of Applied Physics, 1993
- Electromigration in thin aluminum films on titanium nitrideJournal of Applied Physics, 1976