Rapid migration of Si atoms along the grain boundaries of electron beam annealed polycrystalline material (in a Si-on-insulator island structure with a Si3N4 and SiO2 cap) was found. An appreciable amount of mass transport was observed in the structure at temperatures which were high enough to melt the grain boundaries but not the bulk material. The results supported the suggestion that the electromigration of Si4+ ions, in molten Si at the grain boundaries, was responsible for the rapid migration of Si atoms.

Y.Hayafuji, T.Yanada, A.Shibata, S.Kawado: Journal of Applied Physics, 1989, 66[8], 3579-84