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Suppression of Void Formation in Si0.5Ge0.5 Alloy Nanowire during Ni Germanosilicidation

Authors

  • Yida Li,

    1. Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
    2. NUS Graduate School for Integrative Sciences and Engineering, Singapore, Singapore
    3. Institute of Microelectronics, A* STAR (Agency for Science Technology and Research), Singapore, Singapore, Singapore
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  • Kavitha Buddharaju,

    1. Institute of Microelectronics, A* STAR (Agency for Science Technology and Research), Singapore, Singapore, Singapore
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  • Xin-Peng Wang,

    1. Institute of Microelectronics, A* STAR (Agency for Science Technology and Research), Singapore, Singapore, Singapore
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  • Sung-Joo Lee,

    1. SAINT (SKKU Advanced Institute of Nanotechnology), Suwon, Gyeonggi-Do, South Korea
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  • Thiam-Leong Thong

    Corresponding author
    1. Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
    2. NUS Graduate School for Integrative Sciences and Engineering, Singapore, Singapore
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  • This work is supported by an A*STAR SERC PSF Grant 102 1010023.(Supporting Information is available online from Wiley InterScience or from the author).

ABSTRACT

The growth mechanism of Ni-germanosilicide in Si0.5Ge0.5 NW with and without silicon dioxide shell encapsulation was investigated using transmission electron microscope imaging with in situ annealing of SiGe NW array samples capped with Ni. At 200 and 400 °C, the interfacial reaction is minimal while at 600 °C, we can observe the gradual formation of a thin Ni-germanosilicide filament for the unconstrained SiGe NW. This observation is concomitant with material loss from the sides of the SiGe NW, which eventually leads to void formation. Energy dispersive X-ray spectroscopy analysis along the SiGe NW shows that Ge atoms out-diffused from the NW toward the Ni source during annealing. Excessive out-diffusion of Ge atoms and void formation are shown to be retarded in the encapsulated SiGe NW with compressive stress.

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