Solidification front stability during zone-melting recrystallization of thin silicon films

Abstract

The effects of constitutional supercooling and scanning speed on the stability of the solidification front during zone-melting recrystallization of thin silicon films were investigated. We found that constitutional supercooling did not effect the stability of the solid/liquid interface for typical concentrations of oxygen, nitrogen, and carbon found in zone-melting recrystallized films. Interface growth was stable for scanning speeds less than 250 μm/s. The critical impurity concentration for which unstable growth is induced for scanning speeds smaller than 250 μm/s was identified. Carbon and nitrogen diffused into the silicon film seem more likely to cause unstable solidification than oxygen.