Nickel precipitation in large-diameter Czochralski silicon

• Published in: Physica. B, Condensed matter Condensed matter, 2004-02, Vol.344 (1), p.407-412
• Main Authors: Xi, Zhenqiang, Yang, Deren, Chen, Jun, Que, Duanlin, Moeller, H.J.
• Format: Article
• Language: English
• Subjects: Cross-disciplinary physics: materials science; rheology; Czochralski silicon; Exact sciences and technology; Growth from melts; zone melting and refining; Materials science; Methods of crystal growth; physics of crystal growth; Nickel; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Precipitation; SIRM; Solid-phase precipitation
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2003.10.020

In comparison with small-diameter (4 in), nickel precipitation in large-diameter (8 in) Czochralski silicon (Cz–Si) under air-cooling or slow-cooling was investigated by scanning infrared microscopy (SIRM) and optical microscopy. It was found that a nickel precipitate-free zone with a thickness of 250 μm near the surface formed in the specimen of small-diameter Cz–Si annealed at 1100°C under air-cooling, while no nickel precipitates could be observed under slow-cooling. However, nickel precipitates could be found in all the specimens of large-diameter Cz–Si annealed at 1100°C despite different cooling rates. These results indicate that nickel precipitation depends not only on the cooling rate but also intrinsic defects or their complexes in Cz–Si. Finally, the mechanism of nickel precipitation in larger-diameter Cz–Si is discussed.