First-principles investigation of the structural stability and electronic properties of Pd doped monoclinic Cu6Sn5 intermetallic compounds
Autor: | Wei-Quan Shao, Sha-Ou Chen, Wen-Cai Lu |
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Rok vydání: | 2014 |
Předmět: |
ab-initio calculations
Materials science Mechanical Engineering Doping Metallurgy Intermetallic intermetallic compounds (IMC) Substrate (electronics) Condensed Matter Physics Electromigration thermal stability Standard enthalpy of formation Crystallography Mechanics of Materials Ab initio quantum chemistry methods lcsh:TA401-492 lcsh:Materials of engineering and construction. Mechanics of materials General Materials Science Thermal stability site occupancy Monoclinic crystal system |
Zdroj: | Materials Science-Poland, Vol 32, Iss 4, Pp 592-596 (2014) |
ISSN: | 2083-134X |
Popis: | Tri-layer Au/Pd/Ni(P) films have been widely used as surface finish over the Cu pads in high-end packaging applications. It was found that a thin (Cu,Pd)6Sn5 IMC layer was beneficial in effective reducing inter-diffusion between a Cu substrate and a solder, and therefore the growth of the IMC layer and the EM (electromigration) processes. In this study, the structural properties and phase stability of monoclinic Cu6Sn5-based structures with Pd substitutions were studied by using the first-principles method. The (Cu,Pd)6Sn5 structure with the 4e site substituted by Pd has the lowest heat of formation and is the most stable among (Cu,Pd)6Sn5 structures. Hybridization of Pd-d and Sn-p states is a dominant factor for stability improvement. Moreover, Pd atoms concentration corresponding to the most stable structure of (Cu,Pd)6Sn5 was found to be 1.69 %, which is consistent with the experimental results. |
Databáze: | OpenAIRE |
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