Impact of Grain Structure and Material Properties on Via Extrusion in 3D Interconnects


In this article, the effects of Cu microstructure on the mechanical properties and extrusion of through-silicon vias (TSVs) were studied based on two types of TSVs with different microstructure. A direct correlation was found between the grain size and the mechanical properties of the vias. Both an analytical model and finite element analysis (FEA) were used to establish the relationship between the mechanical properties and via extrusion. The effect of via/Si interface on extrusion was also studied by FEA. The results suggest small and uniform grains in the Cu vias, as well as stronger interfaces between the via and Si led to smaller via extrusion, and are thus preferable for reduced via extrusion failure and improved TSV reliability.


Civil, Architectural and Environmental Engineering

Keywords and Phrases

Finite element method; Grain size and shape; Interfaces (materials); Mechanical properties; Microstructure; Three dimensional integrated circuits; 3-D interconnects; 3D integration; Extrusion failures; Grain size; Through silicon vias; Extrusion; FEA; Interface; Via extrusion

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


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Publication Date

01 Jul 2015