High undercooling of bulk molten silicon by containerless processing

When containerless electromagnetic levitation processing was applied to elemental semiconductor Si using a two-step heating method proposed by the present authors, a substantial degree of undercooling up to 420 K (0.25Tm, Tm is the melting temperature, 1685 K for Si) has been reproducibly achieved in slowly cooled silicon droplets ( ∼ 7.6 mm in diameter). The microstructural change from faceted twins grown at low or intermediate undercoolings to...