Effect of ion irradiation of amorphous-silicon films on their crystallization

The change in the structure of amorphous Si films implanted with inert-gas ions and chemically active impurity was investigated by transmission electron microscopy and electron diffraction methods. It was shown that as a result of radiation-induced formation of thermally stable vacancy complexes, Si films irradiated with Ar+ and P+ ions with doses above 7 x 10(15) cm(-2) do not crystallize up to temperature 680 degrees C. It was established that crystallization of Si films after implantation of lower doses of P+ ions accelerates the growth of grains in the films as a compared with the unirradiated films. A model of the mechanism by which the ion irradiation influences the crystallization of Si films is discussed. (C) 1998 American Institute of Physics.