Crystal grain nucleation in a-Si: a way to engineer the pooly-Si morphology

摘要

The soild pahse crystallization of chemical vapor deosited amorphous silicon films onto oxidized siionc wafers, induced by rapid thermal annealing has been extensively investigated. The morphological evolution of the amorphous twoards the olycrystalline phase has been monitored by transmission electron microscopy analysis. The results have been interpreted in terms of a hyscial model containing few free parameters related to the thermodynamica, properties of amorphous silcion and to the kinetical mechanisms of crystal grain growth at the early stages of transformation. On the basis of this model we have developed a computer simulation code wich allows us to predict the final polycrystalline silicon morphology providing information on grain size distribution, average grain radius, and grain poundary lenth per unit area.