ROLE OF CRITICAL SIZE OF NUCLEI FOR LIQUID-PHASE EPITAXY ON POLYCRYSTALLINE SI FILMS

Liquid-phase epitaxy of Si on fine-grained polycrystalline Si seeding films reveals the effect of a critical size of nuclei. As a consequenc e, during deposition appreciable parts of fine-grained polycrystalline Si films dissolve in the initially supersaturated growth solution. Th e observed dependences of the nucleation density on supersaturation an d saturation temperature are in agreement with the concept of the crit ical size of nuclei as predicted by thermodynamic considerations. A co mparison of nucleation densities obtained in liquid-phase epitaxy expe riments and grain size distributions in seeding films allows to confir m the theoretically predicted critical grain size of about 500 nm.