Y silicide thin films with good properties are prepared by using Y metallic ions implantation into silicon. The structure of the implanted layer is analysed by glancing incidence backscattering and channelled low angle omergence analysis. It is found that the implanted region consists of three layers with different lattice distortion density. The first layer is a continual polycrystal yttrium silicide layer with thickness of ￣ 100nm to 120nm. Its lattice distortion ratios for fluxes of 25 μ A/cm2and 50μA/cm2 are 25% and 52%

respectively. The second layer is a high defect density region with thickness of 200nm. The third layer is a low lattice distortion density region with thickness of 120nm. The depth profiles of the Si to Y ratio provide important information for the study of Y silicide.