Aluminum-induced crystallization of amorphous silicon: preparation effect on growth kinetics

Abstract

The kinetics of Al-induced crystallization of amorphous silicon (a-Si) are studied by variation of the thickness of an Al-oxide layer between the initial Al and a-Si films. The results show that the thickness of this Al-oxide layer strongly determines the nucleation time and the number of Si-grains (nucleation) and has only little influence on the growth velocity of the grains. The diameter of the grains increases in good approximation linearly with time and is strongly influenced by the annealing temperature. The activation energies for the growth velocity v g and the nucleation time t n were determined to be 1.8 and 1.9 eV, respectively. The general behavior suggests that the process kinetics of the aluminum-induced layer exchange are determined by the silicon diffusion across the interface which can be altered by the thickness of the oxide layer.