Spatial melt instabilities in radiatively melted crystalline silicon

Abstract
Strongly nonplanar melting of polished and oxidized single crystalline silicon heated by intense incoherent light is reported. Although irradiation is uniform, the surface breaks up into an array of distinctly faceted molten segments separated by solid unmelted regions. The melt depth can have a sawtooth appearance and is always nonuniform. We show that initiation of melting at discrete sites must be caused by the presence of a nucleation barrier and that the phase coexistence is sustained because of the difference in light coupling to the solid and to the liquid Si. Faceting of the molten regions is then a simple, although rarely observed, consequence of melting from inside the crystal. We also show that phase coexistence at the irradiated surface assures steady-state heat flow in the samples over a wide range of input powers.

This publication has 4 references indexed in Scilit: