Book contents
- Electromigration in Metals
- Electromigration in Metals
- Copyright page
- Dedication
- Contents
- Preface
- 1 Introduction to Electromigration
- 2 Fundamentals of Electromigration
- 3 Thermal Stress Characteristics and Stress-Induced Void Formation in Aluminum and Copper Interconnects
- 4 Stress Evolution and Damage Formation in Confined Metal Lines under Electric Stressing
- 5 Electromigration in Cu Interconnect Structures
- 6 Scaling Effects on Microstructure of Cu and Co Nanointerconnects
- 7 Analysis of Electromigration-Induced Stress Evolution and Voiding in Cu Damascene Lines with Microstructure
- 8 Massive-Scale Statistical Studies for Electromigration
- 9 Assessment of Electromigration Damage in Large On-Chip Power Grids
- Index
- References
4 - Stress Evolution and Damage Formation in Confined Metal Lines under Electric Stressing
1D Analysis
Published online by Cambridge University Press: 05 May 2022
- Electromigration in Metals
- Electromigration in Metals
- Copyright page
- Dedication
- Contents
- Preface
- 1 Introduction to Electromigration
- 2 Fundamentals of Electromigration
- 3 Thermal Stress Characteristics and Stress-Induced Void Formation in Aluminum and Copper Interconnects
- 4 Stress Evolution and Damage Formation in Confined Metal Lines under Electric Stressing
- 5 Electromigration in Cu Interconnect Structures
- 6 Scaling Effects on Microstructure of Cu and Co Nanointerconnects
- 7 Analysis of Electromigration-Induced Stress Evolution and Voiding in Cu Damascene Lines with Microstructure
- 8 Massive-Scale Statistical Studies for Electromigration
- 9 Assessment of Electromigration Damage in Large On-Chip Power Grids
- Index
- References
Summary
The momentum exchange between lattice atoms and conduction electrons together with the stress gradient along the metal wire embedded into the rigid confinement are two major driving forces for electromigration-induced evolution of stress and vacancy concentration. The growth of mechanical stress causes an evolution of a variety of defects that are inevitably present in the metal, leading to void formation. It affects the electrical properties of the interconnect. In order to estimate the time to failure caused by voiding, the kinetics of stress evolution should be resolved until the first void is nucleated. Then the analysis of the void size evolution should be performed in order to trace changes in resistances of individual voided lines and vias. In this chapter, we review the major results that have been achieved with the 1D phenomenological EM model. We demonstrate its capability to predict the transient and steady-state distributions of the vacancy concentration and the hydrostatic stress, a void nucleation, and its growth, and also a drift of small voids along a metal wire. Despite its simplified nature, the 1D model is capable of addressing the confinement effect of ILD/IMD dielectric on EM-induced degradation, and also the effect of metal grain structure.
Keywords
- Type
- Chapter
- Information
- Electromigration in MetalsFundamentals to Nano-Interconnects, pp. 80 - 126Publisher: Cambridge University PressPrint publication year: 2022