Crystallization kinetics of amorphous germanium

Abstract

The variation of conductivity in amorphous germanium layers, due to crystallization, has been studied. The fraction which has crystallized is deduced from the variation of conductivity. Depending upon the conditions of preparation, the crystallization is induced at germanium-substrate interface (around 380 °C) or in the bulk (around 450 °C). The interpretation of the variation with time of the crystallized fraction, in terms of surface or bulk induced crystallization, allows the determination of the growth rate and of the initial concentration and size of the crystallites. The variation with the temperature of the growth rate is in good agreement with previously published results. The value found for the initial size of the crystallites is confirmed by electron microscopy observations.