Orientation selection by zone-melting silicon films through planar constrictions

Recrystallization of encapsulated Si films on SiO2 by zone-melting produces films composed of several grains approximately 1 mm wide and extending the length of the scan. Within grains there are sub-boundaries. We report a technique for producing recrystallized Si films of a single orientation. The technique consists of patterning polysilicon with a narrow, planar constriction and passing a molten zone through it so that only one orientation propagates beyond the constriction. We also show that sub-boundaries can be eliminated in the constriction.