Suppression of low angle grain boundaries in seeded thick Si films recrystallized between SiO2 layers

We observe a marked suppression in the formation of low angle grain boundaries (sub-boundaries) during the graphite strip heater recrystallization of thick Si films over buried islands of SiO2. For 27-μm-thick Si films, areas exceeding 1×1 mm2 have been recrystallized on SiO2 which are completely free of grain boundaries and sub-boundaries, but which contain dislocations in other configurations. Moreover, we find the density of these remaining dislocations to be much reduced near the upper and lower SiO2 interfaces.