Surface modification of CaF2 in atomic layer scale by electron beam exposure

Surface modification of CaF2/Si(111) was studied for the purpose of 1 ML adsorption of group-V atoms on a fluoride surface which is applicable to heteroepitaxy of III—V compound semiconductors on CaF2. By using Rutherford backscattering (RBS) and X-ray photoelectron spectroscopy (XPS), it was found that 1 ML of As and P were successfully adsorbed on a CaF2 surface, and that a 1 ML self-limiting adsorption of As for the electron beam exposure was realized. Also, we propose a model for the adsorption conditions depending on the substrate temperature during surface modification.