Surface tension measurement of molten silicon by the oscillating drop method using electromagnetic levitation

Abstract

The surfacetension of molten silicon was successfully measured by an oscillating drop method using electromagnetic levitation over a wide temperature range from 1100 to 1500°C including the undercooling condition of ΔT ≈ 300 K. Single crystals of silicon heavily doped with B and Sb (resistivity as low as ) were successfully melted and levitated. The surfacetension of molten silicon was 783.5 × 10⁻³ N/m at the melting point of 1410°C within the measurement accuracy of 3–4%; its temperature coefficient was −0.65 × 10⁻³ N/m·K. Secondary ion mass spectroscopy (SIMS) analysis showed that O and Sb evaporated during melting, while the B concentration after melting was unchanged. This means that surfacetension and its measured temperature dependence correspond to those for a contamination-free silicon melt.