(a) Fabrication process of amorphous silicon nanofilm by using PLD method, (b) TEM images with nanofilm structure of amorphous silicon, (c) preparing process of silicene crystal by using coherent electron beam to irradiate amorphous silicon nanofilm, and (d) TEM image of spot shape occurring with coherent electron beam irradiating surface (left), and TEM image of the silicene crystal (right).