Scaling effect of interfacial reaction on intermetallic compound formation in Sn/Cu pillar down to 1 μm diameter
Source abstract
Abstract
Abstract Different diameter Sn/Cu pillars varying from 30 to 1 μm have been made by focus ion beam, and the solid state reaction to form Cu6Sn5 in these pillars has been studied. An increased Cu-Sn reaction rate to form Cu6Sn5 was observed as the pillar diameter decrease from 20 to 1 μm when annealed at 185 and 195 °C. With the shrinking of pillar size, surface diffusion becomes important as compared to grain boundary and lattice diffusion in the Cu-Sn interfacial reaction. Also, surface diffusion induced Kirkendall voids was observed to locate at the peripheral area just above Cu of the Cu-Sn pillars. A simple kinetic model of surface diffusion controlled intermetallic compound growth of Cu6Sn5 is proposed for pillars with diameter below 5 μm. What is essential in the model is that we assume a rapid interstitial diffusion of Cu in Sn, and we are able to calculated surface diffusivity of Cu on Cu6Sn5. At 185 °C, the surface diffusivity is about 3.1 × 10−7 cm2/s and the activation energy is about 0.2 ± 0.1 eV/atom.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Electronic Packaging and Soldering Technologies · 3D IC and TSV technologies · Aluminum Alloy Microstructure Properties
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (19)
Show source-provided references
1. Synergistic effect of electromigration and Joule heating on system level weak-link failure in 2.5 D integrated circuits10.1063/1.4932598 ↗
2. Size effect on ductile-to-brittle transition in Cu-solder-Cu micro-joints
3. Reliability challenges in 3D IC packaging technology10.1016/j.microrel.2010.09.031 ↗
4. Size effect model on kinetics of interfacial reaction between Sn-xAg-yCu solders and Cu substrate10.1038/srep07117 ↗
5. Formation and resettlement of (AuxNi1−x) Sn4 in solder joints of ball-grid-array packages with the Au/Ni surface finish10.1007/s11664-000-0010-y ↗
6. A metastable phase of tin in 3D integrated circuit solder microbumps10.1016/j.scriptamat.2015.02.009 ↗
7. Electromigration induced failure on lead-free micro bumps in three-dimensional integrated circuits packaging10.1063/1.4737154 ↗
8. Morphologies, orientation relationships and evolution of Cu6Sn5 grains formed between molten Sn and Cu single crystals10.1016/j.actamat.2008.01.055 ↗
9. Sn-Cu intermetallic grain morphology related to Sn layer thickness10.1007/s11664-007-0270-x ↗
10. Effect of volume in interfacial reaction between eutectic Sn-3.5% Ag-0.5% Cu solder and Cu metallization in microelectronic packaging10.1007/s11664-005-0225-z ↗
11. Tu · 2014 · 178
12. An x-ray diffraction and calorimetric investigation of the compound Cu6Sn510.1007/BF02643268 ↗
13. Diffusion in copper and copper alloys. part I. volume and surface self-diffusion in copper10.1063/1.3253129 ↗
14. Use of a laser diffraction pattern to study surface self-diffusion of metals10.1063/1.1754937 ↗
15. Surface self-diffusion measurements on copper10.1002/pssb.19680250120 ↗
16. The surface self-diffusion of copper as affected by environment10.1016/0001-6160(64)90077-X ↗
17. The surface morphology of a growing crystal studied by thermal energy atom scattering (TEAS)10.1016/S0039-6028(87)80550-2 ↗
18. Predicting trends in rate parameters for self-diffusion on FCC metal surfaces10.1016/S0039-6028(02)01916-7 ↗
19. Low-temperature direct copper-to-copper bonding enabled by creep on highly (111)-oriented Cu surfaces10.1016/j.scriptamat.2014.01.040 ↗