Formation of crystalline Si nanodots in SiO2 films by electron irradiation

Amorphous SiO2 transforms into crystalline Si by 200 kV electron irradiation at ambient temperature. The transformation of amorphous SiO2 to crystalline Si takes place in two steps; the first step involves transformation of amorphous SiO2 into amorphous Si, while the second step is the crystallization of amorphous Si. Valence electron ionization is determined as the key factor for the transformation from SiO2 to amorphous Si; beam heating and knock-on displacement are responsible for the transformation from amorphous Si to crystalline Si. The energy threshold for the crystallization of amorphous Si is determined to be 150.2 kV.