Temperature Dependence of the Electrical Resistivity of Molten Silicon

The temperature dependence of the electrical resistivity of molten silicon was measured based on the direct-current four-probe method in the temperature range from the melting point (1,415° C) to 1,630° C. The variation of the resistivity in this temperature region was less than 0.7%, which is much smaller than previously reported values. The measured resistivity near the solodification point was about 72×10-6 Ω cm, which is about 8% smaller than previously reported values. The resistivity of molten silicon showed a local minimum in the range from 1,450° C to 1,500° C. The resistivity of molten silicon was calculated based on Ziman's formula. The temperature dependence of the measured resistivity was not reproduced when the structure factor S(Q) calculated by a simple hard-sphere model was substituted into Ziman's formula, but was reproduced by using the experimental data of S(Q) measured by Waseda which shows the first peak of asymmetric shape. This result suggests that the specific melt structure of molten silicon has a significant effect on the resistivity.