SUBSTITUTIONAL CARBON IN GERMANIUM
SUBSTITUTIONAL CARBON IN GERMANIUM
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锗中的替代碳
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
S. Öberg
中科院分区：
文献类型：
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作者：
L. Hoffmann;J. C. Bach;B. Nielsen;P. Leary;R. Jones;S. Öberg
Carbon impurities implanted into single-crystalline germanium are studied with infrared absorption spectroscopy and ion channeling. After implantation of $^{12}mathrm{C}^{+}$ at room temperature and subsequent annealing at 350 ifmmode^circelse extdegreefi{}C, a sharp infrared absorption line is observed at 531 ${mathrm{cm}}^{mathrm{ensuremath{-}}1}$. When $^{12}mathrm{C}^{+}$ is substituted by $^{13}mathrm{C}^{+}$, the line shifts down in frequency to 512 ${mathrm{cm}}^{mathrm{ensuremath{-}}1}$ and co-implantation of $^{12}mathrm{C}^{+}$ and $^{13}mathrm{C}^{+}$ does not give rise to additional lines. Therefore, the 531-${mathrm{cm}}^{mathrm{ensuremath{-}}1}$ line represents a local vibrational mode of a defect containing a single carbon atom. Channeling measurements are carried out around the 〈100〉, 〈110〉, and 〈111〉 axes in $^{12}mathrm{C}^{+}$-implanted samples annealed at 450 ifmmode^circelse extdegreefi{}C. The analysis of the data shows that 31ifmmodepmelse extpmfi{}3 % of the carbon atoms are located at substitutional sites, while the remaining carbon atoms appear to be located randomly. The population of the substitutional site and the intensity of the 531-${mathrm{cm}}^{mathrm{ensuremath{-}}1}$ mode have identical temperature dependencies. It is concluded that the 531-${mathrm{cm}}^{mathrm{ensuremath{-}}1}$ mode is the three-dimensional ${mathrm{T}}_{2}$ stretch mode of substitutional carbon. The effective charge of the mode is determined to be (3.4ifmmodepmelse extpmfi{}0.5)e.mAb initio local density functional cluster theory is applied to calculate the structure and the local vibrational modes of substitutional carbon in germanium. The calculated frequencies and isotope shifts for the ${mathrm{T}}_{2}$ stretch mode are in good agreement with the observations.
Carbon impurities implanted into single-crystalline germanium are studied with infrared absorption spectroscopy and ion channeling. After implantation of $^{12}mathrm{C}^{+}$ at room temperature and subsequent annealing at 350 ifmmode^circelse extdegreefi{}C, a sharp infrared absorption line is observed at 531 ${mathrm{cm}}^{mathrm{ensuremath{-}}1}$. When $^{12}mathrm{C}^{+}$ is substituted by $^{13}mathrm{C}^{+}$, the line shifts down in frequency to 512 ${mathrm{cm}}^{mathrm{ensuremath{-}}1}$ and co-implantation of $^{12}mathrm{C}^{+}$ and $^{13}mathrm{C}^{+}$ does not give rise to additional lines. Therefore, the 531-${mathrm{cm}}^{mathrm{ensuremath{-}}1}$ line represents a local vibrational mode of a defect containing a single carbon atom. Channeling measurements are carried out around the 〈100〉, 〈110〉, and 〈111〉 axes in $^{12}mathrm{C}^{+}$-implanted samples annealed at 450 ifmmode^circelse extdegreefi{}C. The analysis of the data shows that 31ifmmodepmelse extpmfi{}3 % of the carbon atoms are located at substitutional sites, while the remaining carbon atoms appear to be located randomly. The population of the substitutional site and the intensity of the 531-${mathrm{cm}}^{mathrm{ensuremath{-}}1}$ mode have identical temperature dependencies. It is concluded that the 531-${mathrm{cm}}^{mathrm{ensuremath{-}}1}$ mode is the three-dimensional ${mathrm{T}}_{2}$ stretch mode of substitutional carbon. The effective charge of the mode is determined to be (3.4ifmmodepmelse extpmfi{}0.5)e.mAb initio local density functional cluster theory is applied to calculate the structure and the local vibrational modes of substitutional carbon in germanium. The calculated frequencies and isotope shifts for the ${mathrm{T}}_{2}$ stretch mode are in good agreement with the observations.