Radiation-Induced Nucleation and Growth of CaSi 2 Crystals, Both Directly during the Epitaxial CaF 2 Growth and after the CaF 2 Film Formation.

The radiation-induced phenomena of CaSi 2 crystal growth were investigated, both directly during the epitaxial CaF 2 growth on Si (111) and film irradiation with fast electrons on Si (111) after its formation, while maintaining the specified film thickness, substrate temperature and radiation dose. Irradiation in the process of the epitaxial CaF 2 film growth leads to the formation of CaSi 2 nanowhiskers with an average size of 5 µm oriented along the direction <110>. The electron irradiation of the formed film, under similar conditions, leads to the homogeneous nucleation of CaSi 2 crystals and their proliferation as inclusions in the CaF 2 film. It is shown that both approaches lead to the formation of CaSi 2 crystals of the 3R polymorph in the irradiated region of a 10 nm thick CaF 2 layer.