Thermomigration-induced void formation in Cu-interconnects - Assessment of main physical parameters
Y. Ding, Olalla Varela Pedreira, Melina Lofrano, Houman Zahedmanesh, Thomas P Chavez, Harold K. Farr, Ingrid De Wolf, Kristof Croes
Abstract
Using a dedicated test structure, the main physical parameters of void formation due to thermomigration (TM) were assessed. Based on physical and electrical void-analyses, we experimentally determined the time to void nucleation and estimated the heat of transport parameter <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$Q^{\ast}= 0.21$</tex> eV for Cu interconnects with CD~1µm, Our studies show that TM has a 6x higher contribution to metal flux compared to the initial stress migration (SM) induced by the coefficient of thermal expansion (CTE) mismatch.
Topics & Concepts
Void (composites)NucleationMaterials scienceThermalThermal expansionFlux (metallurgy)ThermodynamicsComposite materialMetallurgyPhysicsCopper Interconnects and ReliabilityElectronic Packaging and Soldering Technologies3D IC and TSV technologies