Erbium silicide films on (100) silicon, grown in high vacuum. Fabrication and properties

High crystalline quality Erbium silicide films with preferred orientation on (100) Si were obtained by (a) erbium deposition on Si in high vacuum and (b) co-deposition of Er and Si in a flux ratio of Si/Er close to 2 and subsequent annealing. Erbium silicide layers of thickness around 50 nm were obtained, which were characterized by X-ray diffraction, Rutherford backscattering spectroscopy (RBS), scanning electron microscopy and electrical measurements, including both resistivity measurements at room and low temperatures and current-voltage measurements on specially prepared Schottky diodes. High crystalline quality (only one orientation in the X-ray diffraction pattern) was obtained in case (a). Films of case (b) seem to be polycrystalline from the X-ray diffraction pattern but they show high channelling yield in channelling RBS. This is attributed to a first layer of good crystalline quality on silicon and a surface layer of less good crystallinity on top. Reduced surface and interface roughness was also obtained in case (b), resulting in current-voltage characteristics corresponding to an ideality factor close to 1.