Quantifying the effect of metal-rich precipitates on minority carrier diffusion length in multicrystalline silicon using synchrotron-based spectrally resolved x-ray beam-induced current

• Published in: Applied physics letters 2005-07, Vol.87 (4), p.044101-044101-3
• Main Authors: Buonassisi, T., Istratov, A. A., Pickett, M. D., Marcus, M. A., Hahn, G., Riepe, S., Isenberg, J., Warta, W., Willeke, G., Ciszek, T. F., Weber, E. R.
• Format: Article
• Language: English
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.1997274

Synchrotron-based, spectrally resolved x-ray beam-induced current (SR-XBIC) is introduced as a technique to locally measure the minority carrier diffusion length in semiconductor devices. Equivalence with well-established diffusion length measurement techniques is demonstrated. The strength of SR-XBIC is that it can be combined in situ with other synchrotron-based analytical techniques, such as x-ray fluorescence microscopy ( μ -XRF) and x-ray absorption microspectroscopy ( μ -XAS), yielding information about the distribution, elemental composition, chemical nature, and effect on minority carrier diffusion length of individual transition metal species in multicrystalline silicon. SR-XBIC, μ -XRF, and μ -XAS measurements were performed on intentionally contaminated multicrystalline silicon, revealing a strong correlation between local concentrations of copper and nickel silicide precipitates and a decrease of minority carrier diffusion length. In addition, the reduction of minority carrier diffusion length due to submicron-sized Cu 3 Si and NiSi 2 precipitates could be decoupled from the influence of homogeneously distributed nanoprecipitates and point defects.