Our recent work on the poly/single crystal Si interface evolution and on the epitaxial realignment under high temperature (∼ 1000°C) rapid thermal annealing is reviewed. The roles of the mucrystalline morphology, of the interfacial native oxide film, of the doping level and of the processing temperature on the realignment kinetics are addressed. Two different realignment modes are observed. For undoped layers a quasi planar interface motion occurs, while in highly doped polycrystalline layers the realignment proceeds via the formation of epitaxial columns and their lateral growth. These two different modes arise from the doping enhancement of the interface kinetics. It is shown that these processes can be interpreted within an Avrami-Mehl-Johnson nucleation and growth scheme. In the early stages of interface realignment the process is controlled by oxide clustering, arising from the evolution of the native oxide …