Evolution of phosphorus-vacancy clusters in epitaxial germanium

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2019-01-14
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en
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Journal of Applied Physics, Volume 125, issue 2
Abstract
The E centers (dopant-vacancy pairs) play a significant role in dopant deactivation in semiconductors. In order to gain insight into dopant-defect interactions during epitaxial growth of in situ phosphorus doped Ge, positron annihilation spectroscopy, which is sensitive to open-volume defects, was performed on Ge layers grown by chemical vapor deposition with different concentrations of phosphorus (∼ 1 × 10 18- 1 × 10 20 cm - 3). Experimental results supported by first-principles calculations based on the two component density-functional theory gave evidence for the existence of mono-vacancies decorated by several phosphorus atoms as the dominant defect type in the epitaxial Ge. The concentration of vacancies increases with the amount of P-doping. The number of P atoms around the vacancy also increases, depending on the P concentration. The evolution of P n-V clusters in Ge contributes significantly to the dopant deactivation.
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Vohra , A , Khanam , A , Slotte , J , Makkonen , I , Pourtois , G , Loo , R & Vandervorst , W 2019 , ' Evolution of phosphorus-vacancy clusters in epitaxial germanium ' , Journal of Applied Physics , vol. 125 , no. 2 , 025701 . https://doi.org/10.1063/1.5054996