Thermal stress during zone-melting-recrystallization of silicon on insulator films: The origin of subboundaries and in-plane orientation?

The effect of thermal stress during zone-melting recrystallization of silicon on insulator films is considered. New experimental results from graphite-strip heated films are drawn upon. It is found that low-angle grain boundaries exhibit an inverse dependence between spacing and tilt angle. This is explained semi-quantitatively by a model in which thermal stress induced film buckling is responsible for the existence of low-angle grain boundaries. It is also suggested that the predominance of the 100> orientation in these films is partly due to thermal stress and the elastic anisotropy of silicon. Thus thermal stress is proposed as the origin of the two major features of zone-melted films.