Amorphization and its elemental process induced by electron irradiation in Si

Recently, it was found that amorphization is induced in silicon by electron irradiation. By systematic examinations, it was clarified that MeV electron irradiation a low temperature below 100 k is necessary for the amorphization. The result means that the amorphization is caused by the accumulation of not point defects but small cascade damages. Moreover, from precise analysis of the dependence of the intensity of halo rings on irradiation energy and dose, it is concluded that the smallest cascade damage that contributes to amorphization includes only about four silicon atoms. Since amorphous silicon (a-Si) induced by electron irradiation is similar to a-Si created by other conventional techniques, there is a possibility that the new amorphization technique by electron beam is also applied to fabricating various artificial Si structures. (author)