Formation and Optical Properties of Thin Mg₂Ge Films on Si(001) Substrate

Abstract:

Thin Mg₂Ge films were grown using two methods: a co-deposition of Ge and Mg on Si substrate kept at room temperature followed by annealing at 200 °C (solid phase epitaxy – SPE) and reactive deposition epitaxy (RDE) of Ge and Mg on Si at 200 °C. Optical properties of these structures were investigated in the photon energy range of 0.02–6.2 eV. Based on optical functions calculation, it was shown that SPE growth results in formation of a crystalline layer of Mg₂Si, which exhibits a strong optical phonon originated from the substrate-film interface. In the case of RDE growth, the amount of Mg₂Si is sufficiently lower, but Mg‑Si-Ge compound phonon appears. The estimate of a fundamental indirect transition value in the film is 0.72 eV for SPE growth method and 0.56 eV for RDE due to the ternary compound Mg-Ge-Si at the film-substrate interface.

• Periodical: Solid State Phenomena (Volume 247)
• Pages: 66-72
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.247.66
• Online since: March 2016
• Authors: Dmitry L. Goroshko*, Evgeniy A. Chusovitin, Konstantin Nickolaevich Galkin, Igor M. Chernev, Nikolay G. Galkin
• Keywords: Band Gap, Germanide, Germanium, Magnesium, Optical Properties, Phonon Structure, Thin Films

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