Study of intermixing and Zr-silicide formation using swift heavy ion irradiation

摘要

Swift heavy ion (SHI) beam induced irradiation is an established technique for investigating structural modifications in thin films depending on the S_e sensitivity of material. Intermixing due to 120 MeV Au ion irradiation at different fluences from 10~(12) to 10~(14) ions/cm~2 has been reported as a function of ion fluence in a-Si/Zr/a-Si thin films on Si substrate. The samples are characterized before (pristine) and after irradiation using Grazing Incident X-ray Diffraction (GIXRD) and Rutherford Backscattering Spectroscopy (RBS), which confirm the formation of ZrSi at thin film interface. It is suggested that mixing is mainly due to electronic energy loss since the energy transferred from high energy ions seems to create a transient molten zone along the ion track. It is found that the interface mixing increases linearly with the increase in ion fluence. The mixing effect explained in the framework of Thermal spike model. The irradiation effect on the surface roughness of the system is measured using Atomic Force Microscopy (AFM) technique. The current conduction mechanism and Schot-tky barrier height are also calculated by taking I-V curves across the Metal/Si junction.