GePb Alloy Growth Using Layer Inversion Method
Germanium–lead films have been investigated as a new direct-bandgap group IV alloy. GePb films were deposited on Si via thermal evaporation of Ge and Pb solid sources using the layer inversion metal-induced crystallization method for comparison with the current laser-induced recrystallization method. Material characterization of the films using x-ray diffraction analysis revealed highly oriented crystallinity and Pb incorporation as high as 13.5% before and 5.2% after annealing. Transmission electron microscopy, scanning electron microscopy, and energy-dispersive x-ray mapping of the samples revealed uniform incorporation of elements and complete layer inversion. Optical characterization of the GePb films by Raman spectroscopy and photoluminescence techniques showed that annealing the samples resulted in higher crystalline quality as well as bandgap reduction. The bandgap reduction from 0.67 eV to 0.547 eV observed for the highest-quality material confirms the achievement of a direct-bandgap material.
KeywordsMetal-induced crystallization Si photonics GePb alloy x-ray diffraction photoluminescence
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- 1.J. Cressler and G. Niu, eds., Silicon-Germanium Heterojunction Bipolar Transistors (Boston: Artech House, 2003).Google Scholar
- 9.J. Margetis, S.A. Ghetmiri, W. Du, B.R. Conley, A. Mosleh, R. Soref, G. Sun, L. Domulevicz, H.A. Naseem, and S. Yu, Electrochem. Soc. Trans. 35, 1830 (2014).Google Scholar
- 22.E. Parthé, Crystal Chemistry of Tetrahedral Structures (Boca Raton: CRC Press, 1964).Google Scholar
- 24.J. Schlipf, J. Frieiro, I. Fischer, C. Serra, J. Schulze, and S. Chiussi, in 40th International Convention on Information and Communication Technology, Electronics and Microelectronics (MIPRO), Opatija (2017), p. 37.Google Scholar
- 25.Q. Zhou, C. Zhan, X. Gong, T.K. Chan, T. Osipowicz, S.L. Lim, E.S. Tok, and Y. Yeo, in 7th International Silicon-Germanium Technology and Device Meeting (ISTDM), Singapore (2014), p. 80.Google Scholar
- 27.K. Sharif, H.H. Abu-Safe, H. Naseem, W. Brown, M. Al-Jassim, and H.M. Meyer, in IEEE 4th World Conference on Photovoltaic Energy Conference (Waikoloa, HI, 2006), pp. 1676--1679. https://doi.org/10.1109/WCPEC.2006.279812.