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Impact and behavior of Sn during the Ni/GeSn solid‐state reaction
Author(s) -
Quintero Andrea,
Gergaud Patrice,
Hartmann Jean-Michel,
Delaye Vincent,
Reboud Vincent,
Cassan Eric,
Rodriguez Philippe
Publication year - 2020
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s1600576720003064
Subject(s) - intermetallic , materials science , transmission electron microscopy , phase (matter) , thermal stability , atomic diffusion , diffraction , diffusion , chemical physics , analytical chemistry (journal) , crystallography , chemical engineering , nanotechnology , metallurgy , chemistry , thermodynamics , optics , physics , organic chemistry , alloy , chromatography , engineering
Ni‐based intermetallics are promising materials for forming efficient contacts in GeSn‐based Si photonic devices. However, the role that Sn might have during the Ni/GeSn solid‐state reaction (SSR) is not fully understood. A comprehensive analysis focused on Sn segregation during the Ni/GeSn SSR was carried out. In situ X‐ray diffraction and cross‐section transmission electron microscopy measurements coupled with energy‐dispersive X‐ray spectrometry and electron energy‐loss spectroscopy atomic mappings were performed to follow the phase sequence, Sn distribution and segregation. The results showed that, during the SSR, Sn was incorporated into the intermetallic phases. Sn segregation happened first around the grain boundaries (GBs) and then towards the surface. Sn accumulation around GBs hampered atom diffusion, delaying the growth of the Ni(GeSn) phase. Higher thermal budgets will thus be mandatory for formation of contacts in high‐Sn‐content photonic devices, which could be detrimental for thermal stability.