Post-growth annealing of germanium-tin alloys using pulsed excimer laser

Journal Article · Tue Jul 14 04:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4926484· OSTI ID:22490786

Wang, Lanxiang; Wang, Wei; Zhou, Qian; Yeo, Yee-Chia ^[1]; Pan, Jisheng; Zhang, Zheng ^[2]; Tok, Eng Soon ^[3]

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1. Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117582 (Singapore)
2. Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Singapore 117602 (Singapore)
3. Department of Physics, National University of Singapore, Singapore 117551 (Singapore)

We investigate the impact of pulsed excimer laser anneal on fully strained germanium-tin alloys (Ge{sub 1−x}Sn{sub x}) epitaxially grown on Ge substrate by molecular beam epitaxy. Using atomic force microscopy, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy, the morphological and compositional evolution of Ge{sub 1−x}Sn{sub x} with Sn content up to 17% after annealing using various conditions is studied. Ge{sub 0.83}Sn{sub 0.17} samples annealed at 80 mJ/cm{sup 2} or 150 mJ/cm{sup 2} have no observable changes with respect to the as-grown sample. However, Ge{sub 0.83}Sn{sub 0.17} samples annealed at 250 mJ/cm{sup 2} or 300 mJ/cm{sup 2} have Sn-rich islands on the surface, which is due to Sn segregation in the compressively strained epitaxial film. For Ge{sub 0.89}Sn{sub 0.11}, significant Sn redistribution occurs only when annealed at 300 mJ/cm{sup 2}, indicating that it has better thermal stability than Ge{sub 0.83}Sn{sub 0.17}. A mechanism is proposed to explain the formation of Sn-rich islands and Sn-depleted regions.

• OSTI ID: 22490786
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 2 Vol. 118; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
ATOMIC FORCE MICROSCOPY
EXCIMER LASERS
FILMS
GERMANIUM
MOLECULAR BEAM EPITAXY
PULSES
SEGREGATION
SUBSTRATES
SURFACES
TIN ALLOYS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY