X-RAY PHOTOELECTRON-SPECTROSCOPY AND SCANNING ELECTRON-MICROSCOPY OF BETA-FESI2 FILMS GROWN BY ION-BEAM-ASSISTED DEPOSITION

This paper reports the investigation of polycrystalline beta-FeSi2 fil ms grown by Ion Beam Assisted Deposition (IBAD), performed by using a broad Ar+ beam bombarding (001) Si substrates during the evaporation o f Fe atoms. Several energies (200-650 eV) and current densities (10-70 muA cm-2) have been used for the Ar+ beam, keeping the Fe evaporation rate at about 0.08 nm s-1. The formation of the silicide was achieved by in situ thermal annealing at T = 600-degrees-C, performed during o r after the deposition process. Rutherford Backscattering Spectroscopy (RBS), Scanning Electron Microscopy (SEM) and X-Ray Photoelectron Spe ctroscopy (XPS) have been used to study the stoichiometry, the morphol ogy and the chemical status of several samples obtained using differen t ion beam parameters. Strong morphological improvements, such as smoo thing and pinhole closing, are observed for the IBAD films grown durin g thermal annealing. The XPS depth profiling technique has been used t o investigate the morphology of the silicide/Si interface.