Journal of Crystal Growth, Vol.401, 732-736, 2014
Impurities, inclusions, and dislocations in multicrystalline silicon grown from well-mixed and poorly mixed melts
This paper presents an experimental study on the interaction between impurities, inclusions, and dislocations in multi-crystalline silicon ingots grown from well-mixed and poorly mixed melts. The ingots were grown in a high-vacuum induction furnace by the vertical Bridgman method and the degree of impurity mixing within the melt was modified by changing the growth rate. Vertical and horizontal slices were prepared from the ingots and analyzed by Fourier transform IR spectroscopy, as well as reflected-light and IR transmission microscopy to measure the axial carbon concentration and the distribution of dislocations or inclusions, respectively. The correlation between individual inclusions and dislocations has been investigated by correlative reflected-light/IR transmission and scanning electron microscopy. The influence of the melt mixing on the segregation of carbon is demonstrated and discussed with respect to the consequences for the formation of inclusions and dislocation clusters in multi-crystalline silicon. (C) 2014 Elsevier B.V. All rights reserved.