|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Advanced Microelectronic Packaging, Emerging Interconnection Technology, and Pb-free Solder
||Damage Mechanisms in TSVs and Back-end Structures due to Thermal Cycling and Electromigration
||Indranath Dutta, Tae-Kyu Lee, Sukeshwar Kannan, Bibekananda Dutta
|On-Site Speaker (Planned)
During thermal cycling of 3D packages, thermal expansion mismatch between copper TSVs and the silicon die results in copper-pumping, which can cause intrusion or protrusion of the TSVs relative to Si. This is a major reliability concern, since it impacts the stability of back-end-of-line (BEOL) structures. Here we report on experiments on TSV-containing chips under thermal cycling (TC) and electromigration (EM) conditions. It is shown that copper-pumping occurs by three mechanisms: (1) plasticity/creep, (2) grain boundary sliding, and (3) interfacial sliding, and can cause localized damage to BEOL structures. A range of defects can occur during TC and EM, namely, microvoids, interfacial cracks, shear-cracks in TSV-caps, and alloying of the TSV with elements from the C4 micro-bumps and bond-pads due to EM. Whereas the extent of Cu-pumping is relatively small during TC, alloying due to EM has severe impact on electrical performance. The origins of these defects are discussed.
||Planned: Supplemental Proceedings volume